摘要
针对目前国内某钢厂生产S355J2钢时产生大量表面横裂纹的现状,利用扫描电镜、EDS能谱仪对铸坯表面横裂纹进行分析,利用Gleeble-1500热模拟试验机对铸坯热塑性进行分析研究,利用透射电镜对试样中析出物的形貌和尺寸进行研究并对析出物进行热力学计算。试验研究结果表明,裂纹处发生硫偏析使晶界处生成硫化物粒子,增加了γ→α转变时的脆性,从而导致横裂纹敏感性增加;试样的低温脆性区为750~910℃,横裂纹敏感区间为745~903℃,低温脆性区间与横裂纹敏感区间基本一致;钢的热塑性随着析出物粒子尺寸的减小而降低,随着奥氏体晶界处铁素体薄膜厚度的增加而降低。
On account of current status quo of S355J2 steel＇s cracks in the production process,surface transverse cracks were analyzed by SEM and EDS,and low temperature brittle zone was detected by Gleeble-1500 thermal simulator.The morphology and size of precipitates were analyzed by using TEM,and thermo dynamical calculations of precipitates were counted.The results indicated that the sulphur segregation at the grain boundary formed sulfides and increased the brittleness of grain boundary whenγ→αtransformation occurred which lead to rise the susceptibility of transverse cracks in steel.The low temperature brittle zone was 750-910℃,and the temperature of transverse crack susceptibility range was 745-903℃,which was in correspondence with the former.The ductility of steel decreased while the size of precipitates decreased,so did the thickness of ferrite film increased.
出处
《炼钢》
CAS
北大核心
2014年第3期69-73,共5页
Steelmaking
基金
国家自然科学基金(51274032)
关键词
低温脆性区
横裂纹敏感区
析出物
铁素体
low temperature brittle zone
temperature range of transverse crack susceptibility
precipitates
ferrite
