The document discusses various heat treatment processes used to alter the properties of metals and alloys. It describes processes like annealing, normalizing, hardening, and tempering. Annealing is used to relieve stress, soften metals, and refine grain size. Normalizing produces a uniform structure and relieves stresses. Hardening involves heating metal and rapidly cooling to produce martensite for hardness. Tempering is then used to reduce brittleness caused by hardening. The document also discusses diagrams like TTT and CCT that are used to determine the effects of different cooling rates on microstructure formation.
this ppt is useful for understanding the concept of heat treatment process in steel.
it gives the idea about the various stages of heat treatment process in details
Ferrous and Non-Ferrous Metals Production with Casting and Forging Ajjay Kumar Gupta
Ferrous and Non-Ferrous Metals Production with Casting and Forging (Aluminium Alloys, Copper Alloys, Magnesium Alloys, Welding and Joining Processes, ARC Welding Processes, Electrode coating, Spot Welding, Allied Processes, Electron Beam Welding, Structural Mills, Forging, Metal Casting processes, Foundry Processes, Tube Mills, Extrusion and Drawing, Surface cracking, Metallic Bond, Water Rinsing, Laser Welding, Projection Welding, Basic Oxygen Furnace, Ferrous Metals, Pig Iron, Manganese, Carbon, Alloy Steel, Wrought Iron )
In metallurgy, a non-ferrous metal is a metal, including alloys, that does not contain iron (ferrite) in appreciable amounts. Generally more expensive than ferrous metals, non-ferrous metals are used because of desirable properties such as low weight (e.g. aluminium), higher conductivity (e.g. copper), non-magnetic property or resistance to corrosion (e.g. zinc). Some non-ferrous materials are also used in the iron and steel industries.
Market Outlook
Global consumption of primary aluminium ingots during the period January to December 2015 (CY2015) increased to ~57.7 million metric tonnes (MMT) from ~54.3 MMT in CY2014, reflecting a growth rate of ~6.4%. However, consumption growth during H2CY2015 was lower, at ~4.2%. Primary aluminium demand during the second half was adversely impacted by consumption of the prevailing stock of semi-finished and finished products in the market. Consumption growth of primary aluminium metal remained at a similar level of ~4.2% in the first quarter of the current calendar year as well.
See more
https://goo.gl/jZy2qv
https://goo.gl/fSIHG7
https://goo.gl/AAsBY5
Contact us:
Niir Project Consultancy Services
106-E, Kamla Nagar, Opp. Spark Mall,
New Delhi-110007, India.
Email: npcs.ei@gmail.com , info@entrepreneurindia.co
Tel: +91-11-23843955, 23845654, 23845886, 8800733955
Mobile: +91-9811043595
Website: www.entrepreneurindia.co , www.niir.org
Tags
How to Start Ferrous and Non-Ferrous Metal Processing Industry in India, Most Profitable Copper Production Business Ideas, Pig Iron Processing Projects, Small Scale Aluminium Manufacturing Projects, Starting a Non-Ferrous Metal Processing Business, How to Start a Ferrous and Non-Ferrous Metal Production Business, Ferrous Metals Based Small Scale Industries Projects, New small scale ideas in special welding processing industry, NPCS, Niir, Process technology books, Business consultancy, Business consultant, Project identification and selection, Preparation of Project Profiles, Startup, Business guidance, Business guidance to clients, Startup Project for Ferrous, Non-Ferrous Metals, Startup Project, Startup ideas, Project for startups, Startup project plan, Business start-up, Business Plan for a Startup Business, Great Opportunity for Startup, Small Start-up Business Project,
The iron-carbon diagram (also called the iron-carbon phase or equilibrium diagram) is a graphic representation of the respective microstructure states depending on temperature (y axis) and carbon content (x axis).
Controlling decarburization during hot rolling of rail steelSrikar Shenoy
Decarburization of steel during hot rolling makes the hot rolled products prone to low fatigue life. This is especially true in the case of hot rolled rail steel and automobile leaf springs. The presentation gives a practical technique to substantially reduce decarburisation and ensure uniform hardness of hot rolled steel. Prevention of welding / sticking of billets at high temperature, reduced scale pits on hot rolled material, reduced scaling and decarburisation due to billet over-heating in furnace and slightly increased yield are some of the other benefits enabled by use of this technique.
Heat treatment 2 by
P.SENTHAMARAI KANNAN,
ASSISTANT PROFESSOR ,
DEPARTMENT OF MECHANICAL ENGINEERING,
KAMARAJ COLLEGE OF ENGINEERING AND TECHNOLOGY,
VIRUDHUNAGAR, TAMILNADU.
INDIA.
this ppt is useful for understanding the concept of heat treatment process in steel.
it gives the idea about the various stages of heat treatment process in details
Ferrous and Non-Ferrous Metals Production with Casting and Forging Ajjay Kumar Gupta
Ferrous and Non-Ferrous Metals Production with Casting and Forging (Aluminium Alloys, Copper Alloys, Magnesium Alloys, Welding and Joining Processes, ARC Welding Processes, Electrode coating, Spot Welding, Allied Processes, Electron Beam Welding, Structural Mills, Forging, Metal Casting processes, Foundry Processes, Tube Mills, Extrusion and Drawing, Surface cracking, Metallic Bond, Water Rinsing, Laser Welding, Projection Welding, Basic Oxygen Furnace, Ferrous Metals, Pig Iron, Manganese, Carbon, Alloy Steel, Wrought Iron )
In metallurgy, a non-ferrous metal is a metal, including alloys, that does not contain iron (ferrite) in appreciable amounts. Generally more expensive than ferrous metals, non-ferrous metals are used because of desirable properties such as low weight (e.g. aluminium), higher conductivity (e.g. copper), non-magnetic property or resistance to corrosion (e.g. zinc). Some non-ferrous materials are also used in the iron and steel industries.
Market Outlook
Global consumption of primary aluminium ingots during the period January to December 2015 (CY2015) increased to ~57.7 million metric tonnes (MMT) from ~54.3 MMT in CY2014, reflecting a growth rate of ~6.4%. However, consumption growth during H2CY2015 was lower, at ~4.2%. Primary aluminium demand during the second half was adversely impacted by consumption of the prevailing stock of semi-finished and finished products in the market. Consumption growth of primary aluminium metal remained at a similar level of ~4.2% in the first quarter of the current calendar year as well.
See more
https://goo.gl/jZy2qv
https://goo.gl/fSIHG7
https://goo.gl/AAsBY5
Contact us:
Niir Project Consultancy Services
106-E, Kamla Nagar, Opp. Spark Mall,
New Delhi-110007, India.
Email: npcs.ei@gmail.com , info@entrepreneurindia.co
Tel: +91-11-23843955, 23845654, 23845886, 8800733955
Mobile: +91-9811043595
Website: www.entrepreneurindia.co , www.niir.org
Tags
How to Start Ferrous and Non-Ferrous Metal Processing Industry in India, Most Profitable Copper Production Business Ideas, Pig Iron Processing Projects, Small Scale Aluminium Manufacturing Projects, Starting a Non-Ferrous Metal Processing Business, How to Start a Ferrous and Non-Ferrous Metal Production Business, Ferrous Metals Based Small Scale Industries Projects, New small scale ideas in special welding processing industry, NPCS, Niir, Process technology books, Business consultancy, Business consultant, Project identification and selection, Preparation of Project Profiles, Startup, Business guidance, Business guidance to clients, Startup Project for Ferrous, Non-Ferrous Metals, Startup Project, Startup ideas, Project for startups, Startup project plan, Business start-up, Business Plan for a Startup Business, Great Opportunity for Startup, Small Start-up Business Project,
The iron-carbon diagram (also called the iron-carbon phase or equilibrium diagram) is a graphic representation of the respective microstructure states depending on temperature (y axis) and carbon content (x axis).
Controlling decarburization during hot rolling of rail steelSrikar Shenoy
Decarburization of steel during hot rolling makes the hot rolled products prone to low fatigue life. This is especially true in the case of hot rolled rail steel and automobile leaf springs. The presentation gives a practical technique to substantially reduce decarburisation and ensure uniform hardness of hot rolled steel. Prevention of welding / sticking of billets at high temperature, reduced scale pits on hot rolled material, reduced scaling and decarburisation due to billet over-heating in furnace and slightly increased yield are some of the other benefits enabled by use of this technique.
Heat treatment 2 by
P.SENTHAMARAI KANNAN,
ASSISTANT PROFESSOR ,
DEPARTMENT OF MECHANICAL ENGINEERING,
KAMARAJ COLLEGE OF ENGINEERING AND TECHNOLOGY,
VIRUDHUNAGAR, TAMILNADU.
INDIA.
Material Engineering,
Heat treating (or heat treatment) is a group of industrial and metalworking processes used to alter the physical, and sometimes chemical, properties of a material. The most common application is metallurgical. Heat treatments are also used in the manufacture of many other materials, such as glass. Heat treatment involves the use of heating or chilling, normally to extreme temperatures, to achieve a desired result such as hardening or softening of a material. Heat treatment techniques include annealing, case hardening, precipitation strengthening, tempering, carburizing, normalizing and quenching
HEAT TREATMENT OF STEELS AND FERROUS, NON FERROUS AND THEIR ALLOYS SHYAM KUMAR Reddy
TOPICS COVERED
HEAT TREATMENT OF STEELS
FERROUS, NON FERROUS AND THEIR ALLOYS
This is used for polytechnic students and engineering students of mechanical engineering
Heat treatment is define as an operation involving heating and cooling of a metal in the solid state with the purpose of changing the properties of material.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
Contact with Dawood Bhai Just call on +92322-6382012 and we'll help you. We'll solve all your problems within 12 to 24 hours and with 101% guarantee and with astrology systematic. If you want to take any personal or professional advice then also you can call us on +92322-6382012 , ONLINE LOVE PROBLEM & Other all types of Daily Life Problem's.Then CALL or WHATSAPP us on +92322-6382012 and Get all these problems solutions here by Amil Baba DAWOOD BANGALI
#vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore#blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #blackmagicforlove #blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #Amilbabainuk #amilbabainspain #amilbabaindubai #Amilbabainnorway #amilbabainkrachi #amilbabainlahore #amilbabaingujranwalan #amilbabainislamabad
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
2. HEAT TREATMENT PROCESS
• PROPERTIES OF METALS AND ALLOYS
CHANGED AS DESIRED HEAT TREATMENT
PROCESS
• Controlled heating and cooling of metals for
the purpose of altering their properties.
3. Purpose of Heat Treatment:
• To relieve stress created during cold working,
welding, casting etc.
• Improve Machinability.
• Change grain size.
• Improve ductility
• Homogenous structure.
• To improve mechanical properties.
• To change the chemical composition.
• To improve magnetic and electrical properties.
4. HEAT TREATMENT
• Heat treatment may be defined as an operation
or combination of operations involved
heating and cooling of metals/alloys to obtain
desired properties.
STAGES OF HEAT TREATMENT:
1. Heating a metal beyond the critical
temperature
2. Holding a temperature for a sufficient period
(time to allow necessary changes)
3. Cooling the metal (Quenching) to change
nature , size, distribution of micro constituents
7. ANNEALING
Annealing is a process of heating the steel slightly
above the critical temperature of steel (723 degrees
Centigrade) and allowing it to cool down very slowly
furnace it self .
8. • STAGES OF ANNEALING:
– HEATING TO THE DESIRED TEMPERATURE
– HOLDING OR SOAKING AT THE TEMPERATURE
– COOLING OR QUENCHING USUALLY AT ROOM
TEMPERATURE.
10. PURPOSE OF ANNEALING
1. To relieve stresses
2. To induce softness
3. To refine grain size
4. To remove gases
APPLICATIONS:
1. Casting
2. Forging
3. Press work
11. TYPES OF ANNEALING PROCESS
• Full Annealing
• Process Annealing
• Stress Relief Annealing
• Spherodising Annealing
• Recrystallisation Annealing
12. FULL ANNEALING
• Full annealing is the process of slowly raising the temperature about
50 ºC (90 ºF) above the Austenitic temperature line A3 or line ACM in
the case of Hypoeutectoid steels (steels with < 0.77% Carbon) and 50
ºC (90 ºF) into the Austenite-Cementite region in the case of
Hypereutectoid steels (steels with > 0.77% Carbon).
• It is held at this temperature for sufficient time for all the material to
transform into Austenite or Austenite-Cementite as the case may be. It
is then slowly cooled at the rate of about 20 ºC/hr (36 ºF/hr) in a
furnace to about 50 ºC (90 ºF) into the Ferrite-Cementite range. At this
point, it can be cooled in room temperature air with natural
convection.
14. Process Annealing
• PURPOSE:
– It is used to soften and increase the ductility
• Material :
– Steel wires and sheet products
• OPERATION:
– Low carbon steels less than 0.25% c heated slightly
below the critical temperature
– It achieve softening and cooled at any desired rate
– The heating is not like that full annealing
• APPLICATION:
– Preparing steel sheets and wires of drawing.
15.
16. STRESS RELIEF ANNEALING
• PUROPSE:
– It is heat treatment process
– Eliminate residual stress induced by casting,
quenching, etc
• CAUSES OF INTERNAL RESIDUAL STRESSES:
– Plastic deformation
– Non uniform cooling of metal
• EFFECTS OF INTERNAL RESIDUAL STRESSES:
– Due to stresses Warpage takes place
• OPERATION:
– Heated range 550-650 degree celcius, held for a
period of time and cooled slowly.
17. RECRYSTALLISATION ANNEALING
• RECRYSTILLATION:
– Stress grains are replaced by new, strain free grains
during heating above a specific minimum temperature
• RECRYSTALLISATION TEMP:
– When the recrystallisation takes place(new grains
formed) that temp is called recrystallisation temp.
• OPERATION:
– Cold worked steels are heated to a recrystallisation temp
and held for some time, and then cooled
• RESULT:
– Stress free grains, increase ductility.
18. SPHEROIDIING ANNEALING
• PURPOSE:
– Medium and high carbon steels are having coarse
pearlite it is too hard for machining.
– So heat treatment to develop sheroidite structure.
– This structure gives maximum softness and ductility
• OPERATION:
– Prolonged heating below the critical temperature
then slow cooling
– Prolonged heating above and below the critical temp
– Holding for several hours followed by slow cooling.
21. Normalizing
• It is similar to full annealing.
• Cooling in air rather than furnace.
• FULL ANNEALING is expensive and time
consuming
• Instead of full annealing, normalising takes place.
OBJECTIVES:
• Refine grainsize
• Increase strength of steel
• Uniform structure
• Relieve of internal stresses
22. NORMALISING
• OPERATION:
– Heated up to 50-60 degree celcius above critical
temperature
– Normalizing contains ferrite and pearlite for hypo
eutectoid steels.
– Pearlite and cementite for hyper eutectoid steels.
27. QUENCHING
• It’s the operation of rapid cooling by dipping
the hot metal piece into a quenching bath.
• The heated steel become much harder and
stronger by a rapid cooling.
28. Quenching Medium
• Cold water
• 5-10% of CAUSTIC SODA
• Liquid salt
• Oil
• Air
• 5-20% of NaCl
• The rate of cooling determines the level of
hardness and microstructure of steel
29. STAGES OF QUENCHING
1. VAPOUR JACKET STAGE
– Time of quenching forms a gaseous layer
2. VAPOUR TRANSPORT COOLING STAGE
1. Gaseous layer is not stable
2. Bubbles nucleate
3. LIQUID COOLING STAGE
1. Metals cools below the boiling point
2. Conduction (solid liquid ) takes place.
30. Hardening(BY QUENCHING)
• Its a process of heating the steel above or
below the critical temperature for a particular
period and then allow to cool by oil or water
rapidly
31. PURPOSE OF HARDENING
• Hardness of the metal can be improved to
resist wear
• Cutting ability of the material can be
improved to cut other material
• OPERATION:
– HEATING
– SOAKING
– COOLING
32.
33. Factors for getting good hardness
• Carbon content:
when the % carbon is less than 0.3% we cannot do the
process, It should be 0.3 – 0.7%C
• Rate of cooling:
To get martensite structure we have to cool suddenly
• SPECIMEN SIZE:
• OTHER FACTORS
– Geometry
– Quenching temp
– Alloying elements
34.
35. TEMPERING
• In the hardening process we obtained
martensite structure . In this structure, the
material having brittle property and also it has
internal stresses.
• For minimizing the hardness and removing the
internal stresses we heat the metal near to
upper critical temp once again after
quenching and let it for some time then cool
slowly by using salt liquid or oil
39. TYPES OF TEMPERING
• Low temperature tempering (150 – 250 ‘ c)
• Medium temperature tempering (350 – 450 ‘ c)
• High temperature tempering (500 – 650 ‘ c)
40. INTERRUPTED QUENCHING
• The rapid cooling of molten metal gives more
problems like
1. induced stresses
2. distortions (warping)
3. crack formation in steel
In order to overcome the disadvantages a modified
quenching is to be followed called interrupted quenching
Two forms of modified Quenching are
MARTEMPERING
AUSTEMPERING
41. MARTEMPERING
(Mar-quenching)
• It’s a interrupted cooling procedure for a steel to
reduce the stresses, distortions and cracking of
steels that may develop during rapid quenching
42. Step-1
Heat the metal to obtain Austenite structure level
Step-2
Quench the austenite steel in hot oil or molten salt at a
temperature just above the martensite start temp.
Step-3
Hold it for some time and stop the treatment before
the transformation of austenite to banite
Step-4
Cool it in a room air.
43.
44. AUSTEMPERING
(isothermal Quenching)
• It’s a isothermal transformation of steel at a temp below
that of pearlite formation and above that of martensite
transformation
• Its usually used to reduce the quenching distortion and
to make a tough and strong steel
• Banite is the structure formed at the end of the process
• ADVANTAGES
Increased ductility , Toughness and reduced distorsion
45. .
Step-1
Heat the metal to austenite temperature
Step-2
Then quench the steel in a molten salt bath at a temp
just above the martensite start temp of the steel.
Step-3
Holding the steel isothermally to allow the austenite to
banite transformation to take place
Step-4
slow cooling to room temperature in air
48. WHY – TTT & CCT DIAGRAMS ?
• The phases martensite and bainite are non-
equilibrium phase that do not appear in fe-fe3 c
(iron-iron carbon) phase diagram
• also strengthening treatment like hardening and
tempering are non-equilibrium process.
• In order to show the influence of varying cooling rates,
that is time, on the transformation of austenite other
types of diagrams are necessary.
• The time temperature transformation or TTT diagram
and the continuous cooling transformation or CCT
diagram are used to explain the things in the cooling
operation
49. .
• Non-equilibrium cooling will result in different
microstructures hence altered properties.
• TTT diagrams are the tools that we can use to
take into account the kinetics of the
transformation.
• They show the relationship between time,
temperature and (percent) transformation.
• There are two types of TTT diagrams:
–Isothermal transformation (IT) TTT diagrams
–continuous cooling transformation (CCT) TTT
diagrams
52. PATHS
what transformations happen in:
– a. Path 1 (Red line)
– b. Path 2 (Green line)
– c. Path 3 (Blue line)
– d. Path 4 (Orange line)
53. PATH I -
(RED)
• a. (Red) The specimen is cooled rapidly to 150
Degree Celcius and let for 20 minutes. The cooling
rate is too rapid for pearlite to form at higher
temperatures; therefore, the steel remains in the
austenitic phase until the Ms temperature is
passed, where martensite begins to form.
• Since 150 Degree Celcius is the temperature at
which half of the austenite transforms to
martensite, the direct quench converts 50% of the
structure to martensite.
• Holding at 150 Degree Celcius forms only a small
quantity of additional martensite, so the structure
can be assumed to be half martensite and half
retained austenite.
54. PATH 2 -
(GREEN LINE)
• b. (Green) The specimen
is held at 250 Degree
Celcius for 100 seconds,
which is not long
enough to form bainite.
• Therefore, the second
quench from 250
Degree Celcius to room
temperature develops a
martensitic structure.
55. Path 3 –
(Blue line)
• c. (Blue) An
isothermal hold at
300 Degree Celcius
for 500 seconds
produces a half-
bainite and half-
austenite structure.
• Cooling quickly
would result in a
final structure of
martensite and
bainite.
56. PATH 4 –
(Orange Line)
• d. (Orange) Austenite
converts completely to
fine pearlite after
eight seconds at 600
Degree Celcius This
phase is stable and
will not be changed on
holding for 100,000
seconds at 600 Degree
Celcius .
• The final structure
obtained while cooling
is fine pearlite.
58. CCT diagram for Fe-C system
It measure the extent of transformation as a function
of time for a continuously decreasing temperature.
Usually materials are cooled continuously, thus
Continuous Cooling Transformation diagrams are
appropriate.
For continuous cooling, the time required for a reaction
to begin and end is delayed, thus the isothermal curves are
shifted to longer times and lower temperatures
Main difference between TTT and CCT diagrams: no
space for bainite in CCT diagram as continuous cooling always
results in formation of pearlite.
65. HARDENABILITY
• Hardenability of steel is defines as that
property which determines the depth and
distribution of hardness induced by quenching
by austenite condition.
• METHOD OF DETERMINING HARDENABILITY :
– Jominy end quench test
66. JOMINY END QUENCH TEST
• The Jominy end quench test is used to measure
the hardenability of a steel.
• This describes the ability of the steel to be
hardened in depth by quenching.
• steel to partially or completely transform from
austenite to some fraction of martensite at a
given depth below the surface
67. • High hardenability allows slower quenches to be used
(e.g. oil quench), which reduces the distortion and
residual stress.
• The test sample is a cylinder with a length of 111.6 mm
(4 inches) and a diameter of 25.4 mm (1 inch).
Jominy test specimen
68. • This is usually at a temperature of 800 to
900°C.
• The test sample is quickly transferred to the
test machine,
• where it is held vertically and sprayed with
a controlled flow of water onto one end of
the sample.
• This cools the specimen from one end,
69.
70. • The hardness is measured at intervals from the
quenched end. The interval is typically 1.5 mm
for alloy steels and 0.75 mm for carbon steels.
• High hardness occurs where high volume
fractions of martensite
• Lower hardness indicates transformation to
bainite or ferrite/pearlite microstructures