(a) The lower yield point for an iron that has an average grain diameter of 1×10−2 mm is 230MPa. At a grain diameter of
Posted: Thu Jul 14, 2022 3:33 pm
(a) The lower yield point for an iron that has an average grain diameter of 1×10−2 mm is 230MPa. At a grain diameter of 6×10−3 mm, the yield point increases to 275MPa. At what grain diameter will the lower yield point be 310MPa ? (7.5 pts) Hint: solve for σ0 and ky first. Start from here: (b) Consider a hypothetical material that has a grain diameter of 2.1×10−2 mm. After a heat treatment at 600∘C for 3 h, the grain diameter has increased to 7.2×10−2 mm. Compute the grain diameter when a specimen of this same original material (i.e., d0=2.1×10−2 mm ) is heated for 1.7 h at 600∘C. Assume the grain diameter exponent n is exactly 2 . (7.25 pts)