冷却模式对集装箱用耐候钢力学性能的影响  

Influence of cooling mode on mechanical properties of weathering steel for container

作　　者：李永亮 张洪波 邝霜 杨玉厚 刘丽萍 汪云辉 Li Yongliang;Zhang Hongbo;Kuang Shuang;Yang Yuhou;Liu Liping;Wang Yunhui(Technology Center of HBIS Group Tang Steel Company,Tangshan Hebei 063016,China)

机构地区：[1]河北钢铁集团唐山钢铁有限责任公司技术中心,河北唐山063016

出　　处：《金属热处理》2019年第2期150-155,共6页Heat Treatment of Metals

基　　金：国家自然科学基金(51674020)

摘　　要：利用显微组织分析、力学性能测试和电子背散射衍射(EBSD)分析等手段系统地研究了轧后冷却模式对集装箱用耐候钢SPA-H显微组织演变、力学性能变化的影响,并对相关相变机制和力学性能改善的机理进行了探讨。结果表明,当卷取温度不变,轧后冷却模式由前端冷却改为适当空冷后末端冷却后,显微组织中珠光体相变受到抑制,铁素体含量增加。钢板屈服强度、屈强比明显下降,拉伸应变硬化指数n值显著下降。采用末端冷却模式,由于应变诱导铁素体形核和长大的时间充足,使变形奥氏体大部分转变为铁素体组织,组织细化程度提高。钢的强化机制由珠光体强化转变为铁素体细晶强化,是力学性能改善的关键。Influence of cooling mode on microstructure evolution and mechanical properties of weathering steel SPA-H for container was studied by microstructure analysis, mechanical test and electron back scattering diffraction( EBSD), related mechanisms of phase transformation and mechanical property improvement were also discussed. The results show that when the coiling temperature is constant,the ferrite transformation is enhanced while the pearlite transformation is suppressed when the after-rolling cooling is delayed from front cooling to after proper air cooling then water cooling. Correspondingly,the yield strength,yield ratio and the tensile strain hardening exponent decease significantly. When the cooling mode is as-above adjusted,most of the deformed austenite is transformed into ferrite with the microstructure is refined due to extension of the nucleation and growth incubation period of strain induced ferrite. The critical factor about the mechanical properties optimization of the steel can be attributed to the ferrite refinement mechanism while pearlite transformation is suppressed.

关 键 词：集装箱用耐候钢 冷却模式 显微组织 屈服强度 拉伸应变硬化指数 

分 类 号：TG142.4[一般工业技术—材料科学与工程]