由于锰的价格低廉以及在材料中的重要作用而成为钢铁工业常用的合金元素。锰含量高时，可使FeMn合金形成的奥氏体在较低温度下存在。加入Si、Al元素可对合金中奥氏体的稳定性产生不同程度的影响，从而使材料在承受外界载荷时呈现出不同的反应。研究表明：Si可降低奥氏体层错能，有利于A→εM相变，从而使合金易产生形状记忆效应。加大变形量，由于大量的奥氏体转变为α′M时体积膨胀，在使材料伸长率提高的同时，强度也得到提高(相变诱发塑性效应)，因此可用作高性能结构件。Al和Mn是提高奥氏体层错能的合金元素。对于Al、Mn含量高的钢，在外力作用下则可通过孪生诱发塑性变形产生孪晶诱发塑性效应，因而材料在具有较高强度的前提下，还具有60%~80%的伸长率。
Manganese was widely used in iron and steel industry because of its low price and important roles. Adding more manganese to iron made the austenite formed by the binary FeMn alloy exist at low temperature. Introducing Si or Al into the FeMn binary alloy would greatly affect stability of the austenite, which gave birth to the formation of austenite twins, and εM or α′M phases in the austenite matrix dependent on alloy composition and deformation temperature under loading. It was found that Si decreased the stacking fault energy of the austenite, and the alloy possessed shape memory effect associated with A→εM phase transformation. Great deformation caused more austenite to transform into α′M phase, hence an increase in plasticity combined with an improvement of strength due to the transformation induced plasticity (TRIP) effect. On the other hand, both Al and Mn increased the stacking fault energy of the austenite, therefore, loading made homogeneous austenitic steels alloyed with more Al and Mn form deformation twins, which played a dominant role in obtaining good elongation of 60%-80%, together with high strength of the steels.
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