热加工对Fe-Mn-Si-Cr合金马氏体相变和SME的影响

Effect of Hot-drawing on Martensitic Transformation and SME in Fe-Mn-Si-Cr Alloy

本文采用电阻分析、Ｘ射线衍射和电子探针等方法，研究了热加工条件对Ｆｅ－Ｍｎ－Ｓｉ基合 金马氏体相变和形状记忆效应（ＳＭＥ）的影响。当合金在热拉并７５０℃退火后发现，正常退火条件 下的ｆcｃ ｈｃｐ马氏体相变受到抑制，材料明显脆化，ＳＭＥ完全丧失。研究表明，这一热加工脆性 是由于合金中非平衡相的沉淀所致。材料重新加热到９３０℃以上，随着相重新溶解过程的完 成，上述热加工脆性得到消除，马氏体相变和ＳＭＥ也得到恢复。

By using resistance measurment, X-ray diffraction and electronic probe analysis, the effect of hotdrawing condition on martensitic transformation and shape memory effect (SME) in Fe-Mn-Si-Cr alloy was studied. Annealing at 750 after hot-drawing shows that the fcc-hcp martensitic transformation and antiferromagnetic transition are suppressed under the normal annealing conditions. The material becomes very brittle and its SME disappeared. The study shows that the brittleness from hot-working is due to the non-equilibrium. precipitation of a phase at 750 in the alloy. After the material is reheated to a temperature higher than 930 , martensitic transformation and SME are also renewed by clearring up of the brittleness.