预应力钢丝断裂原因分析

Reason Analysis on Fracture of Prestressed Steel Wires

通过化学成分分析、金相检验、低倍检验以及力学性能测试等方法,对82B盘条在拉拔成预应力钢丝过程中发生断裂的原因进行了分析。结果表明:造成82B盘条拉拔时发生脆断的主要原因是由于原料中存在严重的碳偏析,轧制时在富碳区出现过热,析出网状和块状渗碳体以及渗碳体魏氏组织;因而在相同的拉拔力作用下,盘条整个横截面上的塑性变形程度不同,容易产生微裂纹,在拉拔过程中发生断裂。

By means of chemical compositions analysis, metallographic examination, macroscopic examination and mechanical properties lest, the fracture reasons of prestressed steel wires during drawing from 82B steel wire rod were analyzed. The results show that the key reason of the brittle fracture was that the raw materials had defects of serious carbon segregation which resulted in overheating at the carbon-rich area and precipitation of mesh and massive cementite and cementite Widmanstatten structure when rolling. So in the same drawing force, the plastic deformation degree of the whole cross section of the wire rod was different, cracks produced and fracture happened during drawing.