薄鋼板におけるα→γ→α変態による集合組織形成

抄録

For the purpose of investigating the formation mechanism of the texture which is developed by ferrite (α)→austenite (γ)→ferrite (α) transformation, the effects of heating and cooling rates during phase transformation and specimen thickness on the transformation texture have been studied by using extra low carbon sheet steel with the initial texture of {111}.
The results obtained are summarized in the following: (1) Rapid heating and rapid cooling produced weak {100} and {111} texture. (2) Rapid heating and slow cooling exhibited both {110} texture and the orientation shifted 2030 degrees away from {100}. (3) Slow heating and slow cooling produced distinct {100} texture. (4) There was much difference in texture between surface and midsection of thick specimen: In the midsection, the texture similar to (1) was formed, independent of heating and cooling rates. While, specimen surface exhibited such textures as (1) to (3). (5) Those results were reasonably and consistently explained on the assumptions that the orientation relationship between bcc and fcc follows the Kurdjumov-Sachs relation, and that during α→γ→α transformation with slow rate such variants preferentially operate that undergo larger elastic work in normal direction of sheet.