高氮不锈钢热轧边部裂纹成因分析

Reason Analysis for Cracks on High Nitrogen Stainless Steel in Hot Rolling

高氮不锈钢在试制生产过程中常出现边裂问题,通过对边裂部位的断裂形貌的观察,断裂部位夹杂物、组织特点及相成分分析,逐步确定该钢边裂的原因:高温区奥氏体和铁素体两相变形不协调,钢中存在大量的碳氮化物、夹杂物,高温塑性低,道次变形量过大时产生相界裂纹并扩展。通过控制热轧过程道次变形量、钢中氧含量、硫含量,控制热轧边裂。

High-nitrogen stainless steels often have edge crack during the trial production process. In this paper, the cause of the steel edge crack is determined gradually by observing the fracture morphology of the edge crack part, the inclusions, microstructure and phase composition analysis of the fracture site. The deformation of austenite and ferrite in high temperature zone aren51 coordinated. There are lots of carbonitrides and inclusions in the steel, and the high temperature plasticity is low. When the pass reduction is too large, the phase boundary crack will occur and expand. The hot rolling edge crack could be controlled by controlling the amount of deformation of the hot rolling process, the oxygen content and the sulfur content in the steel.