【摘要】 利用全自动相变仪和Ｘ射线衍射仪，对一种含Ｍｎ－Ｎｉ双相热模具钢的马氏体相变特征，以及淬火加热温度、中温等温和二次加热对马氏体相变的影响进行了研究。结果表明，马氏体转变体积分数ｆ＿ｍ随淬火加热温度的升高而减少，Ｍ＿ｓ点却随温度的升高呈现出先降后升的变化趋势。在中温区等温和经二次加热处理，由于碳化物的析出，可增大ｆ＿ｍ和提高Ｍ＿ｓ点。更多还原

【Abstract】 The characteristic of martensitic transformation of a dual-phase hot die steel containing nickel and manganese has been investigated by fully automatic transformation dilatometer and X-ray diffractometer.The effects of austenitizing temperature,isothermal treatment in medium temperature range and secondary heating on the transformation have also been studied. The results show that volume fraction (f_m)of martensite transformed decrease with increasing austenitizing temperature,however,M_S first decreases and then increases with increasing the temperature. It is Because the carbides precipitation during isothermal treatment and secondary heat treatment would increase both f_m and M_S.更多还原