Here is a heat treatment that could help determine the carbon content of the steel:
1. Reheat the steel to above its upper critical temperature to fully austenitize it.
2. Quickly quench it in oil or water to transform the austenite to martensite.
3. Measure the hardness of the resulting martensite. Higher carbon steels will have a higher hardness.
4. Compare the measured hardness to known hardness values for different carbon contents after a similar heat treatment. This could provide an estimate of the carbon content.
The idea is that the hardness of the martensite is dependent on the carbon content. By inducing a full martensitic transformation, the carbon content
various types of steel basically low carbon steels and alloy steels and how the alloying elements alter the various properties of steels , a detailed study & analysis
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
'Iron seemeth a simple metal but in its nature are many mysteries’. Many, but not all,of these mysteries have been solved over the past three hundred years using the combined skill of the foundryman and the knowledge of the scientist to provide today's design engineer with a family of casting alloys that offer a virtually unique combination of low cost and engineering versatility.
The various combinations of low cost with castability , strength,
Machinability , hardness, wear resistance ,corrosion resistance, thermal conductivity and damping are unequalled among all casting alloys and It makes Cast Iron most widely used metal in engineering purpose .
various types of steel basically low carbon steels and alloy steels and how the alloying elements alter the various properties of steels , a detailed study & analysis
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
'Iron seemeth a simple metal but in its nature are many mysteries’. Many, but not all,of these mysteries have been solved over the past three hundred years using the combined skill of the foundryman and the knowledge of the scientist to provide today's design engineer with a family of casting alloys that offer a virtually unique combination of low cost and engineering versatility.
The various combinations of low cost with castability , strength,
Machinability , hardness, wear resistance ,corrosion resistance, thermal conductivity and damping are unequalled among all casting alloys and It makes Cast Iron most widely used metal in engineering purpose .
I hope You all like it. I hope It is very beneficial for you all. I really thought that you all get enough knowledge from this presentation. This presentation is about materials and their classifications. After you read this presentation you knowledge is not as before.
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TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
AIRCRAFT GENERAL
The Single Aisle is the most advanced family aircraft in service today, with fly-by-wire flight controls.
The A318, A319, A320 and A321 are twin-engine subsonic medium range aircraft.
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Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
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.
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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.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
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.
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.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
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
1. Cast Irons
•iron-carbon alloys with more than 2.11% carbon
•It pass through the eutectic reaction during
solidification.
•Properties
•Inexpensive
•Have good fluidity
•Have low liquidus temperature
•Readily castable
2. Cast Irons
•typically cast iron contains 2–4% C
and 0.5–3% Si
•Effect of Si
•reduces the amount of carbon contained in
the eutectic. carbon equivalent (CE):
•Enhances oxidation and corrosion resistance
by forming a tight adhering surface oxide.
•It is a graphite stabilizing element.
•Eutectic Reaction in Cast Irons
•Metastable phase diagram
•Stable rxn
3.
4. Cast Irons
• The microstructure of cast iron has two extremes
1. Liquid austenite + Fe3C (white cast iron)
2. Liquid austenite + graphite (gray, ductile…)
• graphite formation is promoted by
– Slow cooling
– High C and Si content
– Heavy or thick section size
– Inoculation particles
– Presence of S, P, Al, Ni, Sn, Mn, Cu, Cobilt, antimony
• Formation of cementite (Fe3C) is favored by
– Fast cooling
– Low C and Si contents
– Thin sections
– Alloying elements, titanium, vanadium, zirconium,
chromium, manganese, and molybdenum
5. Types of Cast Iron
• Depending on chemical composition, cooling
rate, types and amount of inoculants that are
used we can have
a. Gray iron
b. White iron
c. Malleable iron
d. Ductile iron
e. Compacted graphite iron
6. • Gray cast iron
– The least expensive and most common type
– Characterized by formation of graphite
– Typical composition ranges from 2.5-4.0% C, 1.0-3.0% Si, and
0.4-1.0% Mn.
– contains small, interconnected graphite flakes that cause low
strength and ductility.
– It is the most widely used cast iron
– It is named for the dull gray color of the fractured surface.
– The gray irons are specified by a class number of 20 to 80.
• Properties
– high compressive strength,
– good machinability,
– good resistance to sliding wear,
– good resistance to thermal fatigue,
– good thermal conductivity, and
– good vibration damping.
7. Gray CI
• Application;
– Damping vibrational energy
• Base structures for machines and heavy equipment
– High resistance to wear.
– High fluidity at casting temperature
• Intricate shapes; Low casting shrinkage allowance.
– (strength is not a primary consideration)
– Tensile strength 120 – 300 MPa
• Small cylinder blocks, cylinder heads, pistons, liners, clutch plates,
transmission cases.
• gears, flywheels, water pipes, engine cylinders, brake discs,
Machinery beds
8.
9. • White cast iron
– is a hard, brittle alloy containing massive amounts of
Fe3C.
– A fractured surface of this material appears white, hence
the name.
– Features promoting formation of cementite over
graphite
• A low carbon equivalent (1.8-3.6 %C, 0.5-1.9%Si, 0.25-0.8%Mn)
and
• Rapid cooling
• A group of highly alloyed white irons are used for
their hardness and resistance to abrasive wear.
10. White CI
• Application:
– brake shoes, shot blasting nozzles, mill liners, crushers,
pump impellers and other abrasion resistant parts.
– wear-resistant surface, example, as rollers in rolling mills.
Generally, white iron is used as an intermediary in the
production of yet another cast iron, malleable iron
• White fracture surface
• No graphite, because carbon forms Fe3C or
more complex carbides
• Abrasion resistant
• Often alloyed
11. • Malleable cast iron
– formed by the heat treatment (in range of 900⁰C) of
unalloyed 3%C white cast iron (carbon equivalent 2.5%C,
1.5%Si)
– the cementite dissociates into its component elements
(graphite clumps, or nodules)
– It exhibits better ductility than gray or white cast irons. It
is also very machinable.
• The production steps
• first stage graphitization: cementite decomposes to
the stable austenite and graphite phases
• second stage graphitization: slow cooling through
eutectoid temperature to make ferritic malleable
iron
12. • when austenite is cooled
in air or oil Pearlitic
malleable iron is obtained
(pearlite or martensite.)
• Drawing: is a heat
treatment that tempers
the martensite or
spheroidizes the pearlite.
Application
Connecting rods, transmission gears, and differential cases
for the automotive industry, and also flanges, pipe fittings,
and valve parts for railroad, marine, and other heavy-duty
services
parts of power train of vehicles, bearing caps, steering
gear housings, agricultural equipment, railroad equipment
13. • Ductile or nodular cast iron
– contains spheroidal graphite particles.
– produced by treating liquid iron with a carbon equivalent
of near 4.3% with magnesium
• Steps
– Desulfurization: CaO is used to remove sulfure and oxygen
from the liquid.
– Nodulizing: Mg in dilute form (MgFeSi alloy) is added, a
residual of 0.03%Mg must be present after treatment in
order for spheroidal graphite to grow
• inoculation: heterogeneous nucleation of the graphite
is essential
• Fading: occurs by the gradual, nonviolent loss of Mg
due to vaporization and/or reaction with oxygen
14. Ductile or nodular cast iron
• Application:
– valves, pump bodies, crankshafts, high-strength gears
(heavy duty gears) and machine, rollers, slides, die
material having high strength and high ductility.
• Inoculation with Ce or Mg or both causes
graphite to form as spherulites, rather than
flakes
• Also known as spheroidal graphite (SG), and
nodular graphite iron
• Far better ductility than grey cast iron
15. • Compacted graphite cast iron: contains rounded
but interconnected graphite also produced
during solidification
• intermediate between flakes and spheres with
numerous rounded rods of graphite that are
interconnected to the nucleus of the eutectic
cell.
• vermicular graphite: forms when ductile iron
fades
• permits strengths and ductilities that exceed
those of gray cast iron, but allows the iron to
retain good thermal conductivity and vibration
damping properties.
16. 16
- Less hard and brittle
- Very weak in tension due to the pointed and sharp end of graphite
flakes, where the failure of component initiated at this point.
- Good during compression which graphite acts as a cushion or sponge
that could absorb the compression energy.
- Low shrinkage in mould due to formation of graphite flakes.
- Good dry bearing qualities due to graphite.
Park BenchSprockets
Manhole Covers
with Frames
GREY CAST IRON PRODUCTS
Gas Burners
THE MICRISTRUCTURE OF
GREY CAST IRON
The mechanical characteristic of Gray cast Irons - summary
17. 17
White Cast Irons - summary
• The composition of Carbon and Silicon contents for white cast
irons are in range between 2.5 to 4.0% and less than 1.0%
respectively.
• With a rapid cooling rate most of the carbon in the cast irons
consist of pearlite and cementite (Fe3C).
• The mechanical characteristic of White cast Irons are as follows:
- Relatively very hard, brittle and not weldable compared to
gray cast iron, since it is obtained from rapid cooling process.
- When it’s annealed, it becomes malleable cast iron.
THE MICRISTRUCTURE
OF WHITE
CAST IRON
• A fracture surface of these alloy has
a white appearance and it is called
white cast iron.
• Typical Uses:
Necessitate a very hard and wear
resistance surface such as rollers in
rolling mills, railroads wheel.
18. 18
Ductile (Nodular) Cast Irons - summary
THE MICRISTRUCTURE
OF DUCTILE
CAST IRON
• Typical Uses:
Valves, pump bodies,
gears crankshafts, and
other machine
components.
• Ductile cast iron, which is sometimes called nodular or spheroidal
graphite cast iron. It gets this name because its carbon is in the
shape of small spheres, not flakes.
• Magnesium or cerium is added to the iron before casting occurs. The
effect of these material is to prevent the formation of graphite flakes
during the slow cooling of the iron.
• The structures of the cast irons is mainly pearlite with nodules of
graphite.
• A heat treatment process can be applied to a pearlite nodular iron to
give a microstructure of graphite nodules in ferrite. The ferrite
structure is more ductile but has less tensile strength than the
pearlite form. It’s also weldable.
TEE pipe
19. 19
Malleable Cast Irons - summary
• Malleable cast iron is produced by the heat treatment of white
cast irons.
• Heating white iron at temperatures 800 c to 900 c for 50 hours in
a neutral atmosphere (to prevent oxidation) causes a
decomposition of the cementite, forming graphite in the form of
clusters/ rossettes surrounded by a ferrite or pearlite matrix
depending on cooling rate.
• The mechanical characteristic of malleable cast iron is similar to
nodular cast iron and give higher strength and more ductility and
malleability. The silicon content is low.
THE MICRISTRUCTURE
OF MALLEABLE
CAST IRON
MALLEABLE CAST
IRON PRODUCTS
CLAMPS
20. Effect of alloying elemets
General Characteristics of White Cast Irons
• White Cast Irons contain Chromium to prevent formation
of Graphite upon solidification and to ensure stability of
the carbide phase.
• Usually, Nickel, Molybdenum, and/or Copper are alloyed
to prevent to the formation of Pearlite when a matrix of
Martensite is desired.
• Fall into three major groups:
• Nickel Chromium White Irons: containing 3-5%Ni, 1-
4%Cr. Identified by the name Ni-Hard 1-4
• The chromium-molybdenum irons (high chromium
irons): 11-23%Cr, 3%Mo, and sometimes additionally
alloyed w/ Ni or Cu.
• 25-28%Cr White Irons: contain other alloying
additions of Molybdenum and/or Nickel up to 1.5%
21. Nickel Chromium
• Produced for more than 50
years, effective materials for
crushing and grinding in
industry.
• Consists of Martensite
matrix, with Nickel alloyed at
3-5% in order to suppress
transformation of Austenite to
Pearlite.
• Chromium usually included
between 1.4-4% to ensure
Carbon phase solidifies to
Carbide, not Graphite.
(Counteracts the Graphitizing
effect of Ni)
•
Abrasion resistance (usually desired property of this
material) increases with Carbon content, but toughness
decreases.
Applications: Because of low cost, used primarily in mining
applications as ball mill liners and grinding balls.
23. Sample Analysis and Identification
• Possible to identify and classify a sample of unknown
cast iron.
• Identification can be accomplished through the use
of many known mechanical, chemical and structural
properties of the cast iron alloys.
• In this example, we will attempte to examine and
identify separate cast iron samples of unknown
composition.
24. Sample Analysis and Identification
• We obtained two samples of
what was initially perceived to be
cast iron. The first being a cooking
pot, and the second a 90° pipe
fitting.
• Both samples were cut, mounted
and polished in a bakelite round,
for microstructure examination.
• Followed by a Rockwell hardness
test of each specimen.
25. Microstructure Analysis
• The two micrographs are shown above, the 90° pipe fitting on the left, and
the cooking pot handle on the right.
• The Rockwell hardness was also measured for both samples, yielding a
hardness of 157 HRB for the fitting, and 120 HRB for the pot handle.
The microstructure analysis was accomplished after
polishing and etching (utilizing a 3% nitric acid solution in
ethanol) to reveal the grains.
26.
27. Microstructure Analysis
for the cooking pot
• Upon analysis of the microstructures, it became
apparent that the cooking pot does not conform to
any common form of cast iron.
• Although the handle fractured in a manner very
similar to that of cast iron, the microstructure shows
little resemblance to those of cast iron.
• Although further analysis would be required, one
possibility is a cast steel material. This would account
for the similarity of its fracture to that of cast iron.
28. Microstructure Analysis
for The 90° fitting
• The 90° fitting shows indications of a
dark graphite surrounded by lighter
colored matrix. The graphite appears to
be in the form of dark rosettes, while
the matrix is a lighter color.
• Upon comparison to the known
structure of different types of cast irons,
it can be seen that the microstructure of
malleable iron most closely matches our
sample.
• To the right is a side-by-side
comparison, with our sample on the
top, and a known Malleable
microstructure on the bottom.
Pipe Sample (150X mag)
Malleable Iron (150X mag)
29. Conclusion
• Cast Iron and historical significance
– Used throughout history since its discovery, stepping stone to the development of
modern technology (First Steam Engine)
• Types of Cast Irons and microstructure
– Grays, Whites, Ductile, Malleable
• Applications
– Automotive, Industrial, Household, Aeronautical, & Construction
• Sample Analysis and Comparison for identification and Classification
– Capability to analyze and compare microstructures to determine Cast Iron Type.
And Hardness measurements to identify heat treatment,
30.
31. 1. Briefly describe the simplest heat
treatment procedure that would be used
in converting a 0.76 wt% C steel from one
microstructure to the other, as follows:
a) Spheroidite to tempered martensite
b) Tempered martensite to pearlite
c) Bainite to martensite
d) Martensite to pearlite
e) Pearlite to tempered martensite
f) Tempered martensite to pearlite
g) Bainite to tempered martensite
h) Tempered martensite to spheroidite
32. Examples
1. Calculate the amounts of ferrite, cementite,
primary microconstituent, and pearlite in the
following steels: (a) 1015, (b) 1035, (c) 1095, and
(d) 10130.
2. Estimate the AISI-SAE number for steels having
the following microstructures.
a. 38% pearlite - 62% primary ferrite
b. 93% pearlite - 7% primary cementite
c. 97% ferrite - 3% cementite
d. 86% ferrite - 14% cementite
33. 3. An unalloyed steel tool used for machining aluminum
automobile wheels has been found to work well, but the
purchase records have been lost and you do not know
the steel’s composition. The microstructure of the steel is
tempered martensite. Assume that you cannot estimate
the composition of the steel from the structure. Design a
treatment that may help determine the steel’s carbon
content.
4. Two samples of steel contain 93% pearlite. Estimate the
carbon content of each sample if one is known to be
hypoeutectoid and the other hypereutectoid.
5. Compute the volume percent of graphite VGr in a 3.5
wt% C cast iron, assuming that all the carbon exists as the
graphite phase. Assume densities of 7.9 and 2.3 g/cm3 for
ferrite and graphite, respectively.
34. 6. Your company is producing class 40 gray cast
iron bar of 1.5in in diameter. But a bar of a class
40 gray iron casting is found to have a tensile
strength of 50,000 psi. Why is the tensile
strength greater than that given by the class
number? What do you think is the diameter of
the test bar
7. You would like to produce a gray iron casting
that freezes with no primary austenite or
graphite. If the carbon content in the iron is
3.5%, what percentage of silicon must you add?
35. 3. An unalloyed steel tool used for machining
aluminum automobile wheels has been found to
work well, but the purchase records have been lost
and you do not know the steel’s composition. The
microstructure of the steel is tempered martensite.
Assume that you cannot estimate the composition
of the steel from the structure. Design a treatment
that may help determine the steel’s carbon
content.
4. Your company is producing class 40 gray cast iron
bar of 1.5in in diameter. But a bar of a class 40 gray
iron casting is found to have a tensile strength of
50,000 psi. Why is the tensile strength greater than
that given by the class number? What do you think
is the diameter of the test bar
36.
37.
38.
39. 2. Briefly describe the simplest continuous cooling
heat treatment procedure that would be used in
converting a 4340 steel from one microstructure to
another.
A. (Martensite + bainite) to (ferrite + pearlite)
B. (Martensite + bainite) to spheroidite
C. (Martensite + bainite) to (martensite + bainite +
ferrite)
40. 3. Name the microstructural products of 4340
alloy steel specimens that are first completely
transformed to austenite, then cooled to room
temperature at the following rates:
A. 10ºC/s
B. 1ºC/s
C. 0.1ºC/s
D. 0.01ºC/s