【摘要】 对热轧过程中轧件内部裂纹的愈合行为进行了实验研究,发现裂纹愈合经历了表面贴合、间断性局部愈合、愈合区扩展及完全愈合4个阶段,以此为依据提出了轧件内部裂纹愈合的机理。其要点是提出裂纹贴合深度新概念,指出随轧制过程进行裂纹贴合深度逐步减小,当局部的贴合深度小于某临界值时,裂纹两侧原子互相作用形成统一晶格,使裂纹出现局部愈合及愈合区扩展。热轧变形中位错运动能促进裂纹愈合。更多还原

【Abstract】 The crack healing process during hot rolling has been investigated.According to the experimental results,the crack healing process goes through four stages: crack surface contact,locally healing discontinuously,healing zone expanding,and global healing.On the basis of above results,the mechanism of crack healing is established.A new concept of crack contact depth is proposed.When the crack contact depth is less than a critical value,the continuity of crack is broken by the action of atoms near crack surfaces which might be caused by the movement of dislocation during deformation,and a local zone heals,then the healing zone expands.更多还原