The results show that the appearance of Widmanstatten structure,upper bainite and martensite in the structure of 20MnSi HRB is the main cause making the yield point disappear.

• 结果表明,魏氏组织较多、轧制缺陷及夹杂物过多是造成脆断的主要原因,并提出了相应的解决措施。