The document discusses various aspects of rolling processes. It defines rolling as a metalworking process that uses compressive forces exerted by rolls to reduce the thickness or change the cross-section of a workpiece. It describes the basic components of a rolling mill and the functions of rolls. It also discusses types of rolling like flat rolling, shape rolling, ring rolling, and thread rolling. Key differences between hot and cold rolling are explained along with advantages and disadvantages of each. Various products produced from rolling like plates, sheets, strips are also mentioned.
Sheet metal characteristics – shearing, bending and drawing operations – Stretch forming operations – Formability of sheet metal – Test methods –special forming processes-Working principle and applications – Hydro forming – Rubber pad forming – Metal spinning– Introduction of Explosive forming, magnetic pulse forming, peen forming, Super plastic forming – Micro forming.
Rolling is a metal forming process where metal stock is passed through one or more pairs of rolls to reduce the thickness and increase the length. There are two main types:
1) Hot rolling is performed above the metal's recrystallization temperature for lower pressure and improved ductility. It produces coarse grains and no residual stresses.
2) Cold rolling is performed below the recrystallization temperature, requiring higher pressures but improving dimensions, finish and strength through residual stresses and elongated grains.
Rolling mills are classified by the number of rolls used, including two-high, three-high, four-high and cluster/sendzimir mills. Continuous mills use multiple stands to continuously roll sheet metal.
The document discusses the process of rolling metals. It begins by defining rolling as the plastic deformation of materials caused by compressive force applied through revolving rolls, which reduces the thickness and increases the length of the workpiece. It then discusses hot rolling and cold rolling processes. Hot rolling is performed above the recrystallization temperature and allows for large deformation, while cold rolling is used for finished sheets and plates. The document also covers grain structure changes during rolling, mechanics of rolling including forces, entry conditions, and roll pressure distribution. It concludes with discussing types of rolling mills.
Rod, wire and tube drawing is a metalworking process where a rod, wire or tube is pulled through a die to reduce its cross-sectional area and increase its length. It involves applying both tensile and compressive forces. Products include wire, rods, and tubes used in applications like electrical wiring, springs and hydraulic tubing. The process offers close dimensional control, lower costs than rolling or extrusion, and can produce very small cross-sections. Lubrication and annealing are important to control work hardening during multiple drawing passes. Dies are commonly made of alloy steels, carbides or diamond to withstand wear from the process.
This document summarizes the hot rolling and cold rolling processes used in mechanical engineering. It defines key terms like ingot, bloom, slab, and billet. It describes the main steps in hot rolling like heating, rough rolling, and finishing rolling. Advantages of hot rolling include reduced energy usage and improved material properties. Disadvantages are non-metallic inclusions and residual stresses. Cold rolling provides better dimensional control and surface finish but requires more force. Common applications of each process are also outlined.
The document discusses various defects that can occur in metal forming processes. It describes the different types of bulk metal forming processes like rolling, forging, extrusion, and drawing. It also covers sheet metalworking processes like bending, drawing, and shearing. The document discusses factors that influence metal forming like material behavior, temperature, strain rate, friction, and lubrication. It explains defects like springback, wrinkles, and provides methods to minimize them.
This document provides definitions and concepts related to roll pass design. It discusses what roll pass designers do, such as designing new mills or extending size ranges on existing mills. Key terms defined include draft, elongation, reduction, spread, contact angle, coefficient of friction, separating force, torque, flow stress, and power curves. The document is presented by Ansar Hussain Rizvi and appears to be the first part of multiple parts on the topic of roll pass design.
The document describes the Vickers hardness test. It uses a diamond pyramid indenter to make an indentation on the material being tested under a specified load ranging from 5 to 120 kg. The indentation left has a square shape regardless of load. The diagonal lengths of the indentation are measured under a microscope and used to calculate the Vickers hardness number, providing a continuous scale of hardness values. Factors like load, indentation shape, and temperature can affect the results. Advantages include consistency of indentation shape and suitability for testing a range of materials and surfaces. A disadvantage is it takes more time than other hardness tests.
Sheet metal characteristics – shearing, bending and drawing operations – Stretch forming operations – Formability of sheet metal – Test methods –special forming processes-Working principle and applications – Hydro forming – Rubber pad forming – Metal spinning– Introduction of Explosive forming, magnetic pulse forming, peen forming, Super plastic forming – Micro forming.
Rolling is a metal forming process where metal stock is passed through one or more pairs of rolls to reduce the thickness and increase the length. There are two main types:
1) Hot rolling is performed above the metal's recrystallization temperature for lower pressure and improved ductility. It produces coarse grains and no residual stresses.
2) Cold rolling is performed below the recrystallization temperature, requiring higher pressures but improving dimensions, finish and strength through residual stresses and elongated grains.
Rolling mills are classified by the number of rolls used, including two-high, three-high, four-high and cluster/sendzimir mills. Continuous mills use multiple stands to continuously roll sheet metal.
The document discusses the process of rolling metals. It begins by defining rolling as the plastic deformation of materials caused by compressive force applied through revolving rolls, which reduces the thickness and increases the length of the workpiece. It then discusses hot rolling and cold rolling processes. Hot rolling is performed above the recrystallization temperature and allows for large deformation, while cold rolling is used for finished sheets and plates. The document also covers grain structure changes during rolling, mechanics of rolling including forces, entry conditions, and roll pressure distribution. It concludes with discussing types of rolling mills.
Rod, wire and tube drawing is a metalworking process where a rod, wire or tube is pulled through a die to reduce its cross-sectional area and increase its length. It involves applying both tensile and compressive forces. Products include wire, rods, and tubes used in applications like electrical wiring, springs and hydraulic tubing. The process offers close dimensional control, lower costs than rolling or extrusion, and can produce very small cross-sections. Lubrication and annealing are important to control work hardening during multiple drawing passes. Dies are commonly made of alloy steels, carbides or diamond to withstand wear from the process.
This document summarizes the hot rolling and cold rolling processes used in mechanical engineering. It defines key terms like ingot, bloom, slab, and billet. It describes the main steps in hot rolling like heating, rough rolling, and finishing rolling. Advantages of hot rolling include reduced energy usage and improved material properties. Disadvantages are non-metallic inclusions and residual stresses. Cold rolling provides better dimensional control and surface finish but requires more force. Common applications of each process are also outlined.
The document discusses various defects that can occur in metal forming processes. It describes the different types of bulk metal forming processes like rolling, forging, extrusion, and drawing. It also covers sheet metalworking processes like bending, drawing, and shearing. The document discusses factors that influence metal forming like material behavior, temperature, strain rate, friction, and lubrication. It explains defects like springback, wrinkles, and provides methods to minimize them.
This document provides definitions and concepts related to roll pass design. It discusses what roll pass designers do, such as designing new mills or extending size ranges on existing mills. Key terms defined include draft, elongation, reduction, spread, contact angle, coefficient of friction, separating force, torque, flow stress, and power curves. The document is presented by Ansar Hussain Rizvi and appears to be the first part of multiple parts on the topic of roll pass design.
The document describes the Vickers hardness test. It uses a diamond pyramid indenter to make an indentation on the material being tested under a specified load ranging from 5 to 120 kg. The indentation left has a square shape regardless of load. The diagonal lengths of the indentation are measured under a microscope and used to calculate the Vickers hardness number, providing a continuous scale of hardness values. Factors like load, indentation shape, and temperature can affect the results. Advantages include consistency of indentation shape and suitability for testing a range of materials and surfaces. A disadvantage is it takes more time than other hardness tests.
This document discusses various sheet metal forming processes and related topics. It begins by outlining some key metal characteristics that affect sheet metal processing, such as elongation, anisotropy, grain size, and residual stress. It then describes basic sheet metal processes like cutting, bending, drawing, and various specific processes like roll forming, spinning, and super plastic forming. The document provides details on processes like shearing, punching, bending, deep drawing, and stretch forming. It also discusses topics such as formability tests, springback, necking, and methods for measuring strain in sheet metal.
The document discusses different types of alloy steels. It begins by explaining that alloy steels have other elements added to iron beyond just carbon in order to improve properties like strength, hardness, toughness, creep resistance, and corrosion resistance.
It then classifies alloy steels into low, medium, and high alloy steels based on their composition. Low alloy steels are further broken down into low carbon, medium carbon, and high/ultra high carbon steels. High alloy steels include stainless steels and tool steels.
Stainless steels are classified as austenitic, ferritic, martensitic, or precipitation hardening depending on their microstructure. Austenitic stainless steels
Rolling is a metal forming process that uses rolls to reduce the thickness and increase the length of metal workpieces. It can be done hot or cold. Hot rolling occurs above the metal's recrystallization temperature and results in a more uniform structure, while cold rolling occurs at room temperature and produces closer tolerances and a better surface finish. The document defines various products of rolling like billets, blooms, slabs, plates, sheets and strips based on their dimensions. It also describes different types of rolling processes like continuous, transverse, shape, ring and thread rolling as well as the types of mills used like two-high, three-high and four-high mills.
The document discusses the rolling process used in mechanical engineering. It begins with introductions and terminology for rolling. It then covers classifications of rolling mills like two high, three high, and four high mills. The types of rolling processes discussed include conventional, transverse, shaped, ring, powder, and thread rolling. Hot and cold rolling are also covered. Key aspects of the rolling process like roll bite condition and common rolling defects are defined. The document concludes with potential problems in rolling and sample multiple choice questions.
Sheet metal is a thin piece of metal between 0.006 and 0.25 inches thick. Sheet metal can be cut, bent, and stretched into various shapes through forming and cutting operations. Common forming operations include bending, deep drawing, and roll forming. Common cutting operations include shearing, blanking, punching, notching, and slitting. Sheet metal workers use tools like dies and presses to perform these operations and shape the metal.
This document discusses impact testing techniques used to evaluate the fracture behavior of materials. It provides background on impact testing and describes the Charpy and Izod impact tests. These tests involve fracturing a notched specimen using a swinging pendulum. The absorbed energy is measured and used to determine the ductile to brittle transition temperature (DBTT) of the material. The DBTT curve shows how absorbed energy and fracture surface morphology change with temperature. Factors that influence the DBTT, such as chemical composition, grain size, and heat treatment are also reviewed. Experimental procedures for conducting impact tests at different temperatures are outlined.
Okay, here are the steps:
1) UTS of 5052-O aluminum = 280 MPa
2) Thickness, t = 1.8 mm
3) Cutting edge length, L = πD = π * 25 mm = 78.5 mm
4) Using the empirical formula:
Fmax = 7.0 * UTS * t * L
= 7.0 * 280 * 1.8 * 78.5
= 3,400 N
So the estimated maximum punch force required is 3,400 Newtons.
This document provides an overview of manufacturing processes and gating systems for casting. It discusses the key elements of a gating system including the pouring basin, sprue, runner, gates, and riser. The objectives and factors affecting the performance of gating systems are outlined. Different types of gating systems like vertical, bottom, and horizontal are described. Formulas related to fluid flow and solidification time are also provided.
Continuous casting is a process used to cast metal into a continuous length. Molten metal is poured into a mold and solidifies into a casting as it travels downward. New molten metal is continuously supplied to the mold to keep the process going and produce a casting of indefinite length. The process requires precise control of parameters like molten metal flow to ensure smooth, continuous casting.
This document provides an overview of cold rolling technology. It discusses the different types of cold rolling mills and their components. It describes the cold rolling process including pickling, cold rolling, annealing and skin passing. It explains process parameters like thickness and width tolerances, flatness control, and defects in cold rolled steel. It also provides details about Tata Steel's cold rolling capabilities including its pickling line, tandem cold mill, annealing and skin passing facilities.
This document discusses common casting defects such as surface defects, internal defects, incorrect chemical composition, and unsatisfactory mechanical properties. It defines casting defects and explains how they reduce output and increase production costs. Specific defects covered include swell, fins, gas holes, shrinkage cavities, hot tears, and cold shuts. For each defect, the causes and remedies are described. Even in modern foundries, the rejection rate can be as high as 20% of total castings produced due to these defects.
Introduction Hot Working and Cold Working of Metals Forging Processes- Open, impression die forging, Closed die forging-forging operation Rolling of metals-types of rolling- Flat strip rolling-shape rolling operation -Defects in rolled parts- Principle of rod and wire drawing-tube drawing -Principle of extrusion Types-hot and cold extrusion.
1. Sheet metal forming operations include bending, stretching, deep drawing, and other processes where sheets are formed. Bending involves shaping a straight length into a curve and can be done using presses or rolls.
2. Deep drawing uses a die and punch to shape flat sheets into cup-shaped parts. Stretch forming clamps sheet edges and stretches the sheet over a die into the desired shape.
3. Successful forming requires considering the material properties, die and process parameters to avoid defects like cracks, wrinkles, and non-uniform thinning. Minimum bend radii, lubrication, and holding pressure all impact the quality of formed parts.
The document discusses bending processes and springback issues. It covers bending, bending processes, factors that influence springback like size effects, methods for predicting and compensating for springback like die design and the displacement adjustment method. It also applies these methods to the bending of 304 stainless steel tubes and discusses the results.
Casting is a manufacturing process where a liquid material is poured into a mold and allowed to solidify. There are several types of casting processes. Permanent mold casting uses reusable molds, usually made of metal. In the gravity process, preheated molds are coated with a refractory material before molten metal is poured in. Once solidified, the casting is removed. Slush casting is a variant that produces hollow castings. Shell mold casting uses a sand-resin mixture applied to a pattern to form a thin-walled reusable mold, allowing for complex geometries and high precision. Die casting forces molten metal into a mold cavity under high pressure to produce parts with excellent dimensional accuracy.
The document discusses different types of furnaces used in foundries for melting metals. It describes cupola furnaces, which are vertical cylindrical furnaces used to melt iron. Cupola furnaces have a charge of coke, metal, and flux layers that are heated by hot exhaust gases rising through the furnace. As the materials are consumed, additional charges can be added. Molten metal emerges from the bottom tap hole while slag is removed from the slag hole. Other furnace types discussed include direct fuel-fired furnaces, crucible furnaces, electric-arc furnaces, and induction furnaces.
Roll pass design in continuous bar millsrahul kishore
The document discusses various topics related to rolling mills and rolling processes. It defines a rolling mill as consisting of at least two cylindrical rolls used to shape or form metal. It describes different types of mill passes based on shape (definite, intermediate) and roll adjustment (open, closed). It provides formulas to calculate parameters for each pass like roll groove dimensions, roll gap, filled width, area reduction, and bite angle. It discusses concepts like number of passes required, spread calculation, and provides thumb rules and flow charts for roll pass design.
The document discusses design considerations for castings. It notes that casting involves pouring molten material into a mold to create complex shapes. Successful casting requires controlling variables like the material, casting method, cooling rate, and gases. The document outlines design considerations like designing parts for easy casting, selecting suitable materials and processes, locating parting lines and gates, and including features like sprues and risers. It also discusses designing parts to avoid defects from things like shrinkage, stress concentrations, and uneven cooling. The document concludes by mentioning some common casting defects and factors in the economics of casting like costs of molds, materials, and production rates.
Continuous casting is a process that solidifies molten metal into a semi-finished billet, bloom, or slab for subsequent rolling. It involves pouring molten metal from a ladle into a tundish, then through a nozzle into a mold where it solidifies into a continuous strand. As the strand exits the mold, it passes through primary and secondary cooling zones before being bent and cut into final pieces. Continuous casting is now the dominant production method for metals like steel due to benefits like improved yield, quality, and energy efficiency compared to batch casting.
The document discusses various metal forming processes including rolling, forging, and extrusion. It describes rolling as reducing thickness of metal between opposing rolls. The main types are flat rolling and shape rolling, with hot rolling being most common. Forging involves compressing metal between dies to shape it. The main types are cold forging, hot forging, drop forging, and press forging. Extrusion uses compression to force metal through a die opening to produce parts with uniform cross-sections like rods.
Roll forming is a metal forming process that uses pairs of rolls to progressively bend and form sheet metal, tubes, or strips into the desired cross-sectional shape. It is commonly used to form lightweight metals like aluminum into strong, rigid parts. The roll forming process strengthens the material and improves properties like hardness and corrosion resistance. Flat rolling is the most widely used metal forming process, accounting for around 90% of forming. It involves passing slabs, strips, sheets, or plates between rolls to reduce thickness and possibly increase width. The workpiece is squeezed between the rolls, reducing thickness through compression. Friction plays an important role in drawing the workpiece into the roll gap for forming. High velocity hydroforming uses high-pressure
Roll forming is a metal forming process that uses pairs of rolls to progressively bend and form sheet metal, tubes, or strips into the desired cross-sectional shape. It is commonly used to form lightweight metals like aluminum into strong, rigid parts. The roll forming process strengthens the material and improves properties like hardness and corrosion resistance. Flat rolling is the most widely used metal forming process, accounting for around 90% of forming. It involves passing slabs, strips, sheets, or plates between rolls to reduce thickness and possibly increase width. The workpiece is squeezed between the rolls, reducing thickness through compression. Friction plays an important role in drawing the workpiece into the roll gap for forming. High velocity hydroforming uses high-pressure
This document discusses various sheet metal forming processes and related topics. It begins by outlining some key metal characteristics that affect sheet metal processing, such as elongation, anisotropy, grain size, and residual stress. It then describes basic sheet metal processes like cutting, bending, drawing, and various specific processes like roll forming, spinning, and super plastic forming. The document provides details on processes like shearing, punching, bending, deep drawing, and stretch forming. It also discusses topics such as formability tests, springback, necking, and methods for measuring strain in sheet metal.
The document discusses different types of alloy steels. It begins by explaining that alloy steels have other elements added to iron beyond just carbon in order to improve properties like strength, hardness, toughness, creep resistance, and corrosion resistance.
It then classifies alloy steels into low, medium, and high alloy steels based on their composition. Low alloy steels are further broken down into low carbon, medium carbon, and high/ultra high carbon steels. High alloy steels include stainless steels and tool steels.
Stainless steels are classified as austenitic, ferritic, martensitic, or precipitation hardening depending on their microstructure. Austenitic stainless steels
Rolling is a metal forming process that uses rolls to reduce the thickness and increase the length of metal workpieces. It can be done hot or cold. Hot rolling occurs above the metal's recrystallization temperature and results in a more uniform structure, while cold rolling occurs at room temperature and produces closer tolerances and a better surface finish. The document defines various products of rolling like billets, blooms, slabs, plates, sheets and strips based on their dimensions. It also describes different types of rolling processes like continuous, transverse, shape, ring and thread rolling as well as the types of mills used like two-high, three-high and four-high mills.
The document discusses the rolling process used in mechanical engineering. It begins with introductions and terminology for rolling. It then covers classifications of rolling mills like two high, three high, and four high mills. The types of rolling processes discussed include conventional, transverse, shaped, ring, powder, and thread rolling. Hot and cold rolling are also covered. Key aspects of the rolling process like roll bite condition and common rolling defects are defined. The document concludes with potential problems in rolling and sample multiple choice questions.
Sheet metal is a thin piece of metal between 0.006 and 0.25 inches thick. Sheet metal can be cut, bent, and stretched into various shapes through forming and cutting operations. Common forming operations include bending, deep drawing, and roll forming. Common cutting operations include shearing, blanking, punching, notching, and slitting. Sheet metal workers use tools like dies and presses to perform these operations and shape the metal.
This document discusses impact testing techniques used to evaluate the fracture behavior of materials. It provides background on impact testing and describes the Charpy and Izod impact tests. These tests involve fracturing a notched specimen using a swinging pendulum. The absorbed energy is measured and used to determine the ductile to brittle transition temperature (DBTT) of the material. The DBTT curve shows how absorbed energy and fracture surface morphology change with temperature. Factors that influence the DBTT, such as chemical composition, grain size, and heat treatment are also reviewed. Experimental procedures for conducting impact tests at different temperatures are outlined.
Okay, here are the steps:
1) UTS of 5052-O aluminum = 280 MPa
2) Thickness, t = 1.8 mm
3) Cutting edge length, L = πD = π * 25 mm = 78.5 mm
4) Using the empirical formula:
Fmax = 7.0 * UTS * t * L
= 7.0 * 280 * 1.8 * 78.5
= 3,400 N
So the estimated maximum punch force required is 3,400 Newtons.
This document provides an overview of manufacturing processes and gating systems for casting. It discusses the key elements of a gating system including the pouring basin, sprue, runner, gates, and riser. The objectives and factors affecting the performance of gating systems are outlined. Different types of gating systems like vertical, bottom, and horizontal are described. Formulas related to fluid flow and solidification time are also provided.
Continuous casting is a process used to cast metal into a continuous length. Molten metal is poured into a mold and solidifies into a casting as it travels downward. New molten metal is continuously supplied to the mold to keep the process going and produce a casting of indefinite length. The process requires precise control of parameters like molten metal flow to ensure smooth, continuous casting.
This document provides an overview of cold rolling technology. It discusses the different types of cold rolling mills and their components. It describes the cold rolling process including pickling, cold rolling, annealing and skin passing. It explains process parameters like thickness and width tolerances, flatness control, and defects in cold rolled steel. It also provides details about Tata Steel's cold rolling capabilities including its pickling line, tandem cold mill, annealing and skin passing facilities.
This document discusses common casting defects such as surface defects, internal defects, incorrect chemical composition, and unsatisfactory mechanical properties. It defines casting defects and explains how they reduce output and increase production costs. Specific defects covered include swell, fins, gas holes, shrinkage cavities, hot tears, and cold shuts. For each defect, the causes and remedies are described. Even in modern foundries, the rejection rate can be as high as 20% of total castings produced due to these defects.
Introduction Hot Working and Cold Working of Metals Forging Processes- Open, impression die forging, Closed die forging-forging operation Rolling of metals-types of rolling- Flat strip rolling-shape rolling operation -Defects in rolled parts- Principle of rod and wire drawing-tube drawing -Principle of extrusion Types-hot and cold extrusion.
1. Sheet metal forming operations include bending, stretching, deep drawing, and other processes where sheets are formed. Bending involves shaping a straight length into a curve and can be done using presses or rolls.
2. Deep drawing uses a die and punch to shape flat sheets into cup-shaped parts. Stretch forming clamps sheet edges and stretches the sheet over a die into the desired shape.
3. Successful forming requires considering the material properties, die and process parameters to avoid defects like cracks, wrinkles, and non-uniform thinning. Minimum bend radii, lubrication, and holding pressure all impact the quality of formed parts.
The document discusses bending processes and springback issues. It covers bending, bending processes, factors that influence springback like size effects, methods for predicting and compensating for springback like die design and the displacement adjustment method. It also applies these methods to the bending of 304 stainless steel tubes and discusses the results.
Casting is a manufacturing process where a liquid material is poured into a mold and allowed to solidify. There are several types of casting processes. Permanent mold casting uses reusable molds, usually made of metal. In the gravity process, preheated molds are coated with a refractory material before molten metal is poured in. Once solidified, the casting is removed. Slush casting is a variant that produces hollow castings. Shell mold casting uses a sand-resin mixture applied to a pattern to form a thin-walled reusable mold, allowing for complex geometries and high precision. Die casting forces molten metal into a mold cavity under high pressure to produce parts with excellent dimensional accuracy.
The document discusses different types of furnaces used in foundries for melting metals. It describes cupola furnaces, which are vertical cylindrical furnaces used to melt iron. Cupola furnaces have a charge of coke, metal, and flux layers that are heated by hot exhaust gases rising through the furnace. As the materials are consumed, additional charges can be added. Molten metal emerges from the bottom tap hole while slag is removed from the slag hole. Other furnace types discussed include direct fuel-fired furnaces, crucible furnaces, electric-arc furnaces, and induction furnaces.
Roll pass design in continuous bar millsrahul kishore
The document discusses various topics related to rolling mills and rolling processes. It defines a rolling mill as consisting of at least two cylindrical rolls used to shape or form metal. It describes different types of mill passes based on shape (definite, intermediate) and roll adjustment (open, closed). It provides formulas to calculate parameters for each pass like roll groove dimensions, roll gap, filled width, area reduction, and bite angle. It discusses concepts like number of passes required, spread calculation, and provides thumb rules and flow charts for roll pass design.
The document discusses design considerations for castings. It notes that casting involves pouring molten material into a mold to create complex shapes. Successful casting requires controlling variables like the material, casting method, cooling rate, and gases. The document outlines design considerations like designing parts for easy casting, selecting suitable materials and processes, locating parting lines and gates, and including features like sprues and risers. It also discusses designing parts to avoid defects from things like shrinkage, stress concentrations, and uneven cooling. The document concludes by mentioning some common casting defects and factors in the economics of casting like costs of molds, materials, and production rates.
Continuous casting is a process that solidifies molten metal into a semi-finished billet, bloom, or slab for subsequent rolling. It involves pouring molten metal from a ladle into a tundish, then through a nozzle into a mold where it solidifies into a continuous strand. As the strand exits the mold, it passes through primary and secondary cooling zones before being bent and cut into final pieces. Continuous casting is now the dominant production method for metals like steel due to benefits like improved yield, quality, and energy efficiency compared to batch casting.
The document discusses various metal forming processes including rolling, forging, and extrusion. It describes rolling as reducing thickness of metal between opposing rolls. The main types are flat rolling and shape rolling, with hot rolling being most common. Forging involves compressing metal between dies to shape it. The main types are cold forging, hot forging, drop forging, and press forging. Extrusion uses compression to force metal through a die opening to produce parts with uniform cross-sections like rods.
Roll forming is a metal forming process that uses pairs of rolls to progressively bend and form sheet metal, tubes, or strips into the desired cross-sectional shape. It is commonly used to form lightweight metals like aluminum into strong, rigid parts. The roll forming process strengthens the material and improves properties like hardness and corrosion resistance. Flat rolling is the most widely used metal forming process, accounting for around 90% of forming. It involves passing slabs, strips, sheets, or plates between rolls to reduce thickness and possibly increase width. The workpiece is squeezed between the rolls, reducing thickness through compression. Friction plays an important role in drawing the workpiece into the roll gap for forming. High velocity hydroforming uses high-pressure
Roll forming is a metal forming process that uses pairs of rolls to progressively bend and form sheet metal, tubes, or strips into the desired cross-sectional shape. It is commonly used to form lightweight metals like aluminum into strong, rigid parts. The roll forming process strengthens the material and improves properties like hardness and corrosion resistance. Flat rolling is the most widely used metal forming process, accounting for around 90% of forming. It involves passing slabs, strips, sheets, or plates between rolls to reduce thickness and possibly increase width. The workpiece is squeezed between the rolls, reducing thickness through compression. Friction plays an important role in drawing the workpiece into the roll gap for forming. High velocity hydroforming uses high-pressure
Rolling is a metal forming process that reduces thickness or changes the cross-section of metal stock by compressive forces from rolls. There are two main types: flat rolling and shape rolling. Rolling can be done hot or cold depending on the temperature of the metal. Key rolling mill configurations include two-high, three-high, and four-high mills. Seamless pipes and tubes are formed through continuous processes without any welds, providing more reliable pressure retention than welded alternatives.
The document discusses various metal forming processes including rolling, forging, extrusion, and sheet metal working. It provides details on:
- Hot and cold working processes for forming metals like rolling, forging, and extrusion. These processes involve changing the shape of metals above or below their recrystallization temperature.
- Different types of rolling mills and how rolling changes the grain structure and properties of metals.
- The basic process of extrusion using direct or indirect methods to form materials into fixed cross-sections.
- Common forming techniques like deep drawing, bending, spinning, and drawing used to work sheet metals.
This document discusses various metal forming processes including rolling, extrusion, forging, and drawing. It provides definitions and descriptions of each process. Rolling involves passing metal through rotating rolls to reduce thickness or shape it. Extrusion uses a press to force heated metal through a die to shape it. Forging shapes heated metal by compressing it with dies or hammers. Drawing shapes metal by pulling it through a die to reduce its cross-sectional area. Each process deforms metal through compression or tension to form parts.
This document discusses various metal forming processes including:
1. Hot and cold working processes such as forging, rolling, extrusion, and drawing. Forging can be open die, impression die, or closed die. Rolling can be flat or shape rolling.
2. The advantages of hot working include lower forces required, ability to produce dramatic shape changes, and potential to combine with casting. Cold working provides better surface finish and precision.
3. Extrusion uses compression to force metal through a die opening. It can produce hollow or complex cross-sections. Wire and bar drawing similarly reduce cross-section by pulling metal through a die.
Metal forming processes use plastic deformation to change the shape of metal workpieces. Rolling is one of the most common metal forming processes, accounting for around 90% of metal shaping. In rolling, the metal workpiece is passed through one or more sets of rolls, reducing the thickness and changing the cross-sectional area under compressive forces applied by the rolls. The geometry of the final product is determined by the shape and contour of the roll gap. Rolling can be performed hot or cold, and is used to produce a wide variety of parts for structural applications and transportation.
Bulk deformation processes like rolling are used to reduce the thickness or change the cross-section of metal workpieces. Rolling involves compressing metal between rotating rolls to produce flat products like plates and sheets. Hot rolling is done above the metal's recrystallization temperature to facilitate greater reduction in thickness than cold rolling. It produces a softer microstructure through recrystallization while cold rolling strengthens metals but makes them more brittle. Both processes impact the mechanical properties and microstructure of metals.
Extrusion is a process that uses pressure to force heated metal material through a die to create parts with a constant cross-section. There are two main types of extrusion: direct and indirect. Direct extrusion involves pushing the material through the die in the same direction as the ram movement, while indirect extrusion moves the material in the opposite direction of the ram. Extrusion can be performed hot or cold depending on the material, with hot extrusion allowing for more complex shapes from more readily extrudable metals like aluminum. Proper die material and lubrication are important for reducing friction during extrusion.
This document provides information on various sheet metal forming processes. It discusses the characteristics of sheet metal and tests used to determine formability. The main sheet metal forming processes covered are tube bending and forming as well as bending of sheet and plate. Tube bending can be done via press bending, rotary drawing, heat induction, roll bending, and sand packing. Sheet and plate bending includes techniques like roll bending, air bending, bottoming, coining, folding, wiping, and rotary bending. Common applications of sheet metal forming in industries like automotive, aircraft, appliances, and furniture are also mentioned.
Production of sheet steel for refrigerator bodyJubair Likhon
Stainless steel, specifically grades 304, 316, and 430, are commonly used for refrigerator construction due to their corrosion resistance. Sheet steel is produced through rolling processes such as hot rolling, cold rolling, and galvanization. Rolling is the most popular technique due to its low cost and ability to produce large quantities with precise dimensions and uniform properties. Defects can occur from issues like roll misalignment but modern rolling processes aim to minimize variations and improve productivity while lowering energy usage and maintenance needs.
Rolling is a metalworking process that reduces thickness by passing metal between rolls. It is commonly used to convert steel ingots into thinner slabs, sheets, and strips. There are different types of rolling including hot, cold, and shape rolling. Hot rolling above the recrystallization temperature allows for large reductions while cold rolling below this temperature produces better surface finishes. Rolling processes are used widely in Pakistan's steel industry by companies like Batala Steel Products and Mughal Steel to manufacture items like pipes, storage tanks, and steel flooring.
Metal rolling is one of the most important metal forming processes. It involves plastically deforming metal between two rolls to reduce thickness and shape the metal. Most metals are hot rolled into basic shapes like blooms and slabs for further manufacturing. The rolls spin in opposite directions to feed and form the metal through compression. Friction must be controlled through lubrication. Rolling refines grain structure and spreads the width of the metal. Different roll materials, sizes, and mill configurations are used depending on the application. Surface defects can occur if scale or dirt are present while internal defects result from improper material distribution.
Extrusion process presentation final (1).pptxAhmedWail2
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2. ROLLING
Deformation process in which work thickness is reduced by
compressive forces exerted by two opposing rolls
The rolling process (specifically, flat rolling)
3. ROLLING
This is the process of reducing the thickness or
changing the cross-section of a work-piece by
compressive forces exerted by a pair of rotating
rolls. or
The process of plastically deforming
metal by passing it between rolls.
The products are flat products, like: plates &
sheets.
Plates are used for structural applications like
bridges, ships & nuclear vessels.
Sheets (generally 6mm or less in thickness) are
used for automotive, beverage cans, office &
kitchen equipment.
4.
5.
6. CONT……..
• Rolling is the most widely used
forming process, which provides high
production and close control of final
product.
• The metal is subjected to high
compressive stresses as a result of
the friction between the rolls and the metal
surface
7.
8. THE ROLLS
The rotating rolls perform two main functions:
• Pull the work into the gap between them by
friction between work-part and rolls
• Simultaneously squeeze the work to reduce
cross section
9. WHERE
IT
IS
DONE
Rolling mill is a machine or a factoryfor
shaping metal by passing it through
rollers
A rolling mill basically consists of
• rolls
• bearings
• a housing for containing these parts
• a drive (motor) for applying power
to the rolls and controlling the
speed
10. TERMINOLOGY
Bloom is the product of first breakdown
of ingot
(cross sectional area > 230 cm2).
Billet is the product obtained from a
further reduction by hot rolling
(cross sectional area > 40x40 mm2).
Slab is the hot rolledingot
(cross sectional area > 100 cm2 and with
a width ≥ 2 x thickness).
12. TYPES OF ROLLING
• Based on work piece geometry :
– Flat rolling - used to reduce thickness of a rectangular
cross section
– Shape rolling - square cross section is formed into a
shape such as an I-beam
• Based on work temperature :
– Hot Rolling – most common due to the large amount
of deformation required
– Cold rolling – produces finished sheet and plate stock
13. Some of the steel products made in a rolling mill
14. FLAT ROLLING AND ITS
ANALYSIS
R = roller radius
p = roll pressure
L = contact length
θ = contact angle
vr = rollspeed
to = initial plate
thickness
tf = final plate thickness
vo = plate entry speed
vf = plate exitspeed
Side view of flat rolling, indicating before and after thicknesses,
work velocities, angle of contact with rolls, and other features.
15. FLAT ROLLING AND ITS
ANALYSIS
• The work enters the gap between the rolls at a velocity vo and
exits at a velocity vf. Because the volume flow rate is constant
and the thickness is decreasing, vf should be larger than vo.
• The roll surface velocity vr is larger than vo and smaller than vf.
This means that slipping occurs between the work and the rolls.
• Only at one point along the contact length, there is no slipping
(relative motion) between the work and the roll. This point is
called the “Neutral Point” or the “No Slip Point”.
16. FLAT ROLLING AND ITS
ANALYSIS
• In flat rolling, the work is squeezed between two rolls
so that its thickness is reduced by an amount called
the draft:
where
d: draft
to: starting thickness
tf : final thickness
d to t f
17. FLAT ROLLING AND ITS ANALYSIS
• Rolling may not be possible (the sheet will not be pulled) if the
draft is large. The maximum draft for successful rolling per pass
is:
Where:
dmax : maximum draft successful rolling perpass
μ : coefficient of friction
R : roll radius
d 2
R
max
to t f
2
R
of passes
Number
18. Example:- A series of cold rolling operations is to be used to reduce
the thickness of a plate from 50 mm down to 25 mm in a reversing two
high mill. Roll diameter =700 mm and coefficient of friction between
rolls and work = 0.15. The specification is that the draft is to be equal
on each pass.
Determine (a) minimum number of passes required, and
(b) draft for each pass.
Solution
4 passes
3.17
0.15 350
50 - 25
of passes
number 2
2
R
to t f
4
50 - 25
of passes
number
per pass
Draft 6.25 mm
to t f
19. HOT ROLLING
Hot rolling is
a metalworking process that occurs above
the recrystallization temperature of the
material.
Hot rolled metals generally have little directionality
in their mechanical properties and deformation
induced residual stresses.
However, in certain instances non- metallic
inclusions will impart some directionality
20. Also includes
cooling ....
Hot rolling is used mainly to produce sheet metal
or simple cross sections, such as rail tracks.
Non-uniformed cooling will
induce a lot of residual
stresses, which usually occurs
in shapes that have a non-
uniform cross-section, such
as I-beams and H-beams.
APPLICATION
21. Advantages Of Hot Rolling Process
Hot rolling can greatly reduce energy consumption and costs.
The metal plastic deformation is high during hot rolling, and the
deformation resistance is low,
which reduces the energy consumption of metal deformation.
Hot rolling can improve the processing performance of metals and
alloys. That is to say, the coarse grains during foundry are broken, the
cracks are healed, the casting
defects are reduced or eliminated, and the as-cast microstructure is
transformed into a
deformed structure to improve the processing properties of the alloy.
Hot rolling usually uses large ingots and large reduction rolling, which
not only improves
production efficiency, but also creates conditions for increasing rolling
speed and achieving
continuous and automated rolling process.
22. Disadvantages Of Hot Rolling Process
After hot rolling, non-metallic inclusions (mainly
sulfides and oxides, as well as silicates) inside the
steel are pressed into thin
sheets, causing delamination (sandwich).
The delamination greatly deteriorates the tensile
properties of the steel in the thickness direction,
and it is possible that interlinear tearing occurs
when the weld is shrunk.
The local strain induced by weld shrinkage often
reaches several times the yield point strain and is
much larger than the strain caused by the load.
Residual stress caused by uneven cooling.
23. The residual stress is the internal
self-phase equilibrium stress without
external force.
The hot-rolled steel of various
sections has such residual stress.
The larger the section size of the
general section steel, the larger the
residual stress.
Although the residual stress is self-
phase-balanced, it still has some
influence on the performance of
steel members under external force.
24. Such as deformation, stability, fatigue and other aspects may
have adverse effects.
Hot rolling does not control the mechanical properties required
for the product accurately, and the microstructure and
properties of the hot rolled product are not uniform.
The strength index is lower than that of the cold work
hardened product, and higher than the fully annealed product,
the
plasticity index is higher than that of the cold work hardened
product, and lower than the fully annealed product.
The thickness of the hot rolled product is difficult to control
and the control precision is relatively poor; the rough Ra value
of
the surface of the hot rolled product is generally 0.5 to 1.5 μm.
Therefore, hot rolled products are generally used as blanks for
cold rolling.
25. COLD ROLLING
Cold rolling occurs with the
metal below its
recrystallization temperature
(usually at room temperature).
It also improves the surface finish and
holds tighter tolerances.
Due to smaller size of the workpieces
and their greater strength than hot
rolled stock, four-high or cluster mills
are used.
Commonly cold-rolled products include
sheets, strips and rods; products being
smaller than the same products that are
hot rolled.
30. Advantages Of Cold Rolling Process
No heating required
Better surface finish obtained
Superior dimension control
Better reproducibility and
interchangeability of parts
Improved strength properties
Directional properties can be
minimized
31. Disadvantages Of Cold Rolling Process
Higher forces required for deformation
Heavier and more powerful equipment
required
Less ductility available
Metal surfaces must be clean and scale-free
Strain hardening occurs (may require
intermediate anneals)
Imparted directional properties may be
detrimental
May produce undesirable residual stresses
32. Application Of Cold Rolling Process
▪
Foil- The Thickness is less than 0.2 mm, used
mainly in the packaging industry Foil is also used
for building insulation, electrical applications and
in the printing industry.
Sheet-Thickness ranges from 0.2 mm and 6mm,
used for a wide variety of industry including
construction where it is used in aluminum siding
and roofing. Sheet is also used in transport sectors
for making automobile body panels, airframes etc.
Plate-It is the rolled product, which is over 6mm
in thickness. It also has a number of applications
including airframes, defence vehicles and
structural components in building
38. CONTINOUS
The objective is to decrease the
thickness of the metal with an
increase in length and with little
increase in width.
39. TRANSVERSE
•Using circular wedge rolls.
•Heated bar is cropped to
length and
fed in transversely between
rolls.
•Rolls are revolved in one
direction.
40. SECTION OR SHAPE
Flat slap is progressively bent into complex shapes
Suitable for producing moulded sections such as irregular
shaped channels and trim.
41. SHAPE-ROLLING OPERATIONS
• Various shapes can be produced by shape rolling
– Bars
– Channels
– I-beams
– Railroad rails
• Roll-pass design requires considerable experience in
order to avoid external and internal defects
42. RING
A specialized type of hot rolling that increases the
diameter of a ring
The resulting grain structure is circumferential, which
gives better mechanical properties
43. RING ROLLING
Deformation process in which a thick-walled ring of smaller diameter
is rolled into a thin walled ring of larger diameter
• As thick-walled ring is compressed, deformed metal elongates,
causing diameter of ring to be enlarged
• Hot working process for large rings and cold working process for
smaller rings
• Applications: ball and roller bearing races, steel tires for railroad
wheels, and rings for pipes, pressure vessels, and rotating
machinery
• Advantages: material savings, ideal grain orientation,
strengthening through cold working
44. RING ROLLING
Ring rolling used to reduce the wall thickness and increase
the diameter of a ring:
(1) start, and (2) completion of process
45. CONTINOUS CASTING
AND HOT ROLLING
• Metal is melted, cast and hot rolled continuously
through a series of rolling mills within the same
process.
46. THREAD
• Rolled threads are produced in a single pass at speeds
far in excess of those used to cut threads.
• Dies are pressed against the surface of cylindrical
blank. As the blank rolls against the in-feeding die
faces, the material is displaced to form the roots of
the thread, and the displaced material flows radially
outward to form the thread's crest.
47. THREAD ROLLING
Bulk deformation process used to form threads on cylindrical parts
by rolling them between two dies
• Most important commercial process for mass producing bolts and
screws
• Performed by cold working in thread rolling machines
• Advantages over thread cutting (machining):
– Higher production rates
– Better material utilization
– Stronger threads due to work hardening
– Better fatigue resistance due to compressive stresses
introduced by rolling
50. Defects in Rolled Products:
Some of the common defects in rolled products are given
below:
(i) Edge Cracking:
Edge cracking generally occurs in rolled ingots, slabs, or
plates. This is due to, either limited ductility of the work metal
or uneven deformation, especially at the edges.
(ii) Folds:
Folds are a defect generally occurs in plate rolling. This is
caused if the reduction per pass is too small.
(iii) Alligatoring:
Alligatoring is the defect, usually occurs in the rolling of slabs
(particularly aluminum and alloys). In this defect, the work
piece splits along a horizontal plane on exit, with the top and
bottom. This defect always occurs when the ratio of slab
thickness to the length of contact fall within the range of 1.4
to 1.65. Fig. 2.15. Shows the defect of Alligatoring.