Abstract：When the cold heading steel rod SWRCH22A is deformed during use， the head of the bolt undergoes cold heading and cracking during the processing of the round head cross bolt. In order to improve the performance of SWRCH22A wire rod and reduce the cracking probability of cold heading， the metal cracking specimens were detected and analyzed by means of metallographic examination， scanning electron microscopy and energy spectrum analysis. The results show that there is no obvious surface defect in the position corresponding to the stem at the cracked head of the bolt， and there is a long slag inclusion on the near surface. The composition of the slag is similar to that of the continuous casting mold. The main reason for the cracking of the SWRCH22A round head cross bolt is that the slag in the continuous casting process causes the slag on the near surface of the material to crack during cold forming.
2018, Vol. 37 
