Q1.For a cylindrical workpiece, the average forging pressure is given by the equ
ID: 1767080 • Letter: Q
Question
Q1.For a cylindrical workpiece, the average forging pressure is given by the equation . (Q1) Pavot (1 + [2uw / 3h]) . i) Use equation (Q1) to calculate the forging force required to reduce the height of a cylindrical stainless steel workpiece by 50% if its initial diameter is 180mm and its initial height is 200mm. Assume the coefficient of friction is 0.2 and the flow stress of the stainless steel is given by the expression ot-1080 02 MPa Will go over, ans-68.41 MN] i) If a safety factor of 2 is used state the capacity of the press required if presses are available in 10 MN steps Will go over, ans 140MN press] Q2. A tensile specimen whose initial length was 50 mm was plastically stretched until its length became 72.5 mm. Calculate the engineering strain and the true strain Engineering strain 22.5/50 0.45 True strain In(final length/original length) 0.37 (2dcp) Q3 working metallic materials in terms of stress, allowable work and changes to metallic grain structure Explain the difference between hot and cold temperature, Answer in table in notes for lecture 1.7Explanation / Answer
02. Given
initial length of the specimen 72.5 mm
Final length of the specimen 50 mm
a. Engineering strain = (Final length - Initial length)/ initial length
= (72.5-50)/50
= 0.45
b. True strain = ln ( final length / original length)
= ln (72.5/50)
= 0.37
3.
It is done at a temperature below the recrystallization temperature.
Less stress required.
COLD WORKING HOT WORKING Hot working is done at a temperature above recrystallization temperature. More stress is required.Less stress required.
Internal and residual stresses are produced. Internal and residual stresses are not produced. Cold working increases ultimate tensile strength, yield point hardness and fatigue strength but decreases resistance to corrosion. In hot working, ultimate tensile strength, yield point, corrosion resistance are unaffected. Crystallization does not take place. Crystallization takes place.Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.