Ou. 3 Chapters 10- 11: Phase Transformations/ Designations, Compositions and Typ Applications for Some Selected Steels (25%) Using the isothermal transformation diagram for an iron-carbon alloy o...
1. Using the isothermal transformation diagram for an iron-carbon alloy of eutectoid composition, specify the nature of the final microstructure (in terms of microconstituents present and approximate percentages of each) of a small specimen that has been subjected to the following time-temperature treatments. In each case assume that the specimen begins at 760°C and that it has been held at this temperature long enough to have achieved a complete and homogeneous austenitic structure (a) Rapidly cool to 400°C, hold for...
Problem 3 (20 pts): Using the phase diagram and isothermal transformation diagram for an iron- carbon alloy of eutectoid composition. Assuming that the specimen begins at 760-C and that it has been held at this temperature long enough to have achieved a complete and homogeneous austenitic structure, answer the following questions: 1400 Eutectoid temerabre 1000 800 400 600 300 400 200 MC90%) 100 200 Time (s) We were unable to transcribe this image Problem 3 (20 pts): Using the phase...
QUESTION 4 (10 points) a. Using the isothermal transformation diagram for iron carbon alloy of eutectoid composition. Specify and sketch the resulting microstructure from the following heat treatments: (Assume that, in each case, the specimen begins at 760 C and that it attains a homogeneous austenite structure) (N.B. ATTACH THE T-T-T DIAGRAM SHEET WITH THE ANSWER SHEET) 11) Cool rapidly to 370 C, hold for 100 s, and then quench to room temperature. [2] Cool rapidly to 250 C, hold...
Make a copy of the isothermal transformation diagram for an iron–carbon alloy of eutectoid composition provided overleaf and then sketch and label time–temperature paths on this diagram to produce the following microstructures: a) 25% martensite and 75% austenite b) 100% fine pearlite c) 25% pearlite, 25% bainite, 45% martensite, and 5% austenite. d) 100% tempered martensite. 800 A 1400 Eutectoid temperature 700 A 1200 A P 600 1000 500 800 AXTIS 400 A 600 300 M(start 50% 200 400 M+A...
Problem 4 The TTT (isothermal transformation) diagram for an iron-carbon alloy with eutectoid 0.78 wt. % C composition is shown on the next page. Describe the microstructure present in a thin strip of 1080 steel (0.80 wt. % C, approximately eutectoid composition) after each step of the following treatments. Assume that the steel is initially 100 % in the austenite phase due to prior homoge- nization by holding at 871 °C for 1 h. (a) Quench in lead at 704...
Using the isothermal transformation diagram for an alloy steel (type 4340) specify the nature of the final microstructure (in terms of micro-constituents present and approximate percentages) of a small specimen that has been subjected to the following time-temperature treatments: In each case assume that the specimen begins at 760°C and that it has been held at this temperature long enough to have achieved a complete and homogeneous austenite structure. (a) (a) Rapidly cool to 400°C, hold for 10 seconds, and...
HW Module 10 Due: March 31, 2019 11:59PM 1- Using the isothermal transformation diagram for an iron-carbon alloy of eutectoid composition (Following Figure), specify the nature of the final microstructure (in terms of micro constituents present and approximate percentages of each) of a small specimen that has been subjected to the following time-temperature treatments. In each case assume that the specimen begins at 760°C (1400°F) and that it has been held at this temperature long enough to have achieved a...
600 4. Chapter 10: Example Problem 10.3 (30 points, 10 points each) Using the isothermal transformation diagram for an iron-carbon -Eutected mere 1400 alloy of eutectoid composition (Figure 10.23), specify the nature roo- of the final microstructure in terms of microconstituents present and approximate percentages) of a small specimen that has been subjected to the following time-temperature treatments. In each case, assume that the specimen begins at 760°C (1400°F) and that it has been held at this temperature long enough...
14) 4. Using the attached iron-iron carbide phase diagram, answer the following: a) Upon slow cooling a 1.0 wt% carbon steel from 900°C: i) At what temperature does the carbide phase appear? ii) How much carbide is present at 729°C? iii) How much carbide is present at 725°C? b) Upon slow cooling a 0.5 wt% carbon steel from 900°C to 725°C: i) What are the compositions and quantities of the two phases present? ii) What are the compositions and quantities...
900 1600 A A+C 404 • Chapter 10 Phase Transformations Figure 10.39 Isothermal transformation diagram for a 1.13 wt% Ciron-carbon alloy: A, austenite; B, bainite; C, proeutectoid ce 800 mentite; M, martensite; P.pearlite. [Adapted from H. Boyer (Editor), Atlas of Isother- mal Transformation and Cooling Transformation Diagrams, 1977. Reproduced by permission of ASM International, Materials Park, OH.) ? 1400 200 A+P 1200 600 1000 500 A+B Temperature (°C) 800 Temperature (°F) 400 A 300 600 50% 200 M(start) 400 M(50%)...