论文部分内容阅读
用复型技术研究含碳0.4%钢的扭转疲劳的起始阶段和短裂纹特性。发现疲劳短裂纹在铁素体中发生并扩展。裂纹增长速度取决于裂纹端部塑性范围的大小和程度。因而每循环的裂纹增长正比于滑移带强度。裂纹扩展的减速和可能停止证明晶界是裂纹扩展的强障碍。升高应力值后,原有的不扩展裂纹可能产生支裂纹或连接其它裂纹继续扩展。这个过程反复到一个或多个主导性裂纹的应力达到能导至破坏的继续增长的临界值为止。
Study on Initial Stage and Short Crack Torsion Fatigue of 0.4% Carbon Steel with Recovering Technology. Short fatigue cracks were found to occur in ferrite and expand. The rate of crack growth depends on the size and extent of the plastic range at the crack tip. Thus the crack growth per cycle is proportional to the slip band strength. Deceleration of crack growth and possible stoppage of strong barriers that demonstrate grain boundaries are crack propagation. Increasing the stress value, the original non-expanding cracks may crack or connect other cracks continue to expand. This process is repeated until the stress of one or more dominant cracks reaches the critical threshold that will lead to continued growth of damage.