9Ni钢的热处理及低温韧度

介绍了不同的热处理规范对9Ni钢的低温韧度的影响,对9Ni钢低温韧度的机理进行了总结与探讨。9Ni钢具有良好低温韧度的机理,一种解释是回转奥氏体阻止裂纹的扩展即裂纹尖端钝化效应。另一种解释是回转奥氏体发生形变诱发马氏体转变,阻止了裂纹的萌生和扩展,还有一种解释是回转奥氏体吸收使铁素体变脆的C、N等元素,使基体得到净化,从而提高低温韧度,即回转奥氏体的净化作用。

Heat Treatment and Low Temperature Toughness of 9Ni Steel

The effects of heat treatment on low temperature toughness of 9Ni steel were introduced, the mechanism of low temperature toughness of 9Ni steel was summarized and discussed. 9Ni steel has the mechanism of excellent cryogenic toughness, first explanation is that reversed austenite prevents the cracks from spreading; second explanation is that reversed austenite produces deformation to induce martensite transformation, which prevents cracks from germinating and extending; Furthermore, third explanation is that reversed austenite absorbs C.N and other elements, which make the ferrite embrittle,and purify the matrix, thereby improving low-temperature toughness of 9Ni steel, i.e the purification action of reversed austenite.