【摘要】 用扫描电镜对18Cr-18Mn-0.7N高氮奥氏体钢的组织及低温脆断断面的晶体学特征进行了分析.结果表明:低温脆断断口上有退火孪晶界断面、沿晶断面及穿晶断面3种断裂刻面.退火孪晶界断面为一光滑、平坦的{111}面,上有折线状台阶,其它3组{111)面上的形变组织在退火孪晶界断面上形成3组交角为60°的直线状平行迹线;沿晶断面为一光滑曲面,{111}面的形变组织在其上形成几组不同交角的曲线状平行迹线;穿晶断面粗糙不平,显示平行于{111}面的台阶、河流花样或棱状花样,它们是不同{111}面上的裂纹在扩展中合并形成的.更多还原

【Abstract】 Microstructures and crystallographic features of low temperature brittle fracture of 18Cr-18Mn-0.7N high nitrogen bearing austenitic steel were investigated by means of scanning electronic microscopy.The results showed that there are three kinds of fracture facets on the fracture surface:annealing twin boundary fracture facet,intergranular fracture facet and transgranular fracture facet.The first facet is a planar and smooth{111}plane with bent steps,and the planar deformations on the other three{111}planes formed a pattern of three sets of straight-lines intersected at 60°on the facet.The second facet is a smoothly curved facet on which the planar deformations on{111} planes formed a pattern of several sets of curved parallel lines that intersected each other at different angles.The third facet is rough and contains steps parallel to{111}plane and river patterns or edge patterns,which is the consequence of coalescence of cracks propagating on different{111}planes.更多还原