在对某热轧态的GCr15棒材进行热剪切下料的过程中,其剪切面有开裂现象。采用宏观观察、超声波检测、化学成分分析、扫描电镜分析及金相检验等方法分析其开裂原因。结果表明:热轧棒材端部的中心应力裂纹是造成剪切开裂的主要原因,棒材端部的中心应力裂纹与棒材轧制后未及时退火或者缓冷有关。

In the process of hot shear blanking of a hot rolled GCr15 bar, there was cracking on the shear surface. The cracking reason was analyzed by macroscopic observation, ultrasonic testing, chemical composition analysis, scanning electron microscope analysis and metallographic examination. The results show that the central stress crack at the end of the hot rolled bar was the main cause of shear cracking, and the central stress crack at the end of the bar was related to the failure of timely annealing or slow cooling after rolling.