薄鋼板のα→γ→α変態集合組織に及ぼす初期方位の影響

Abstract

By using low and extra low carbon sheet steels with the initial texture of {111}, {110}, or {100}, the effect of transformation condition has been investigated on the texture developed by ferrite (α)→austenite (γ)→ferrite (α) transformation. (1) In specimens with the {111} texture, slow heating to transformation temperature produced {100} texture, whereas rapid heating gave the texture consisting of {110} and orientations shifted away 20 to 30 degrees from {100}. (2) Rapid heating gave {100} texture as far as transformation was performed for long-duration of time as high temperature. (3) The before-mentioned results did not change with variation in annealing atomosphere. (4) In specimens with the {100} texture, slow heating and rapid heating produced respectively {100} texture and the texture consisting of {110} orientation and that shifted away 20 to 30 degrees from {100}. (5) In specimens with the {110} texture, slow heating produced {110} texture, while rapid heating gave {100} texture. (6) To explain these experimental results explicitly and consistently, the new theory on the transformation texture was proposed: Such variants with the Kurdjumov-Sachs relation that undergo larger elastic work in normal direction of sheet tend to operate preferentially with decreasing rate of traransformation.