60Si2Mn大规格弹簧扁钢崩料原因分析

Analysis of Crumbling Fracture of Large Size 60Si2Mn Flat Steel for Springs

对影响60Si2Mn大规格弹簧扁钢剪切崩料的化学成分、O/N含量、脱碳层深度、夹杂级别、硬度和显微组织原因进行了检验分析,认为造成大规格60Si2Mn弹簧扁钢崩料的主要原因是扁钢心部出现了正偏析带和负偏析带,导致扁钢横断面性能不均匀,在冲击载荷作用下,容易在偏析区域和交界处出现应力集中,造成剪切崩料。通过炼钢采取新的工艺措施后,减轻了扁钢心部正偏析带和负偏析带的产生,弹簧扁钢崩料现象消失。

Factors such as the chemical composition,O/N content,decarburization depth,classes of inclusions,hardness and microstructure which might cause the crumbling of the large size 60Si2 Mn flat steel for springs at cutting were analyzed.It was found that the main reason was the existence of a positive segregation band and a negative segregation band at the core of the flat steel,which caused non-uniformity in the cross-sectional property of the flat steel and easily formed stress concentration in the segregation zone and at the boundary under impact load,leading to material crumbling at cutting.After adopting new steelmaking technological measures,both of the positive segregation band and negative segregation band at the core of the flat steel have been reduced and the phenomenon of material crumbling at cutting was eliminated.