影响中碳Mn系铸态马氏体/贝氏体复相钢冲击值的因素

针对一种使用在混凝土泵车输送管道上的中碳Mn系铸态新型马氏体/贝氏体复相钢的冲击韧度及其影响因素进行了研究,通过金相显微镜和扫描电镜分析了这种钢的微观组织、断口形貌、夹杂物、缩孔缩松对无缺口冲击值的影响.结果表明,铸件凝固时形成枝晶的主轴冲击方向的夹角与冲击值有很大的关系.枝晶凝固时的收缩导致在其周围形成的大量缩松,以及马氏体和贝氏体组织的尺寸是造成冲击值较低的主要原因.

Factors of Affecting Impact Value of Medium Carbon Mn-system Bainite/Martensite Duplex Cast Steel

The impact value of medium carbon Mn-system bainite/martensite duplex cast steel for the pipe in concrete pump truck and its affecting factors were studied,and the effect of microstructure,fracture morphology,non-metallic inclusions,shrinkage cavity and porosity on non-notch impact value of the cast steel was analyzed by OM and SEM.The results show that the angle between dendrite axis direction and impact test direction has a great effect on impact value.A lot of shrinkage cavity and porosity resulte in shrinking in the castings during solidification.The lower impact energy is mostly caused by a lot of shrinkage cavity and porosity and the size of the bainite and martensite in microstructure.