钛强化对700MPa高强耐候钢性能的影响及改进

针对10和14mm厚规格700MPa级高强度耐候钢屈服强度和抗拉强度偏低的情况，利用金相显微镜和扫描电镜进行了组织观察，调查了炼钢和热轧工艺过程控制情况，研究了碳化钛的固溶和析出强化对力学性能的影响。结果表明，加热制度执行不够导致碳化钛未完全固溶，冷却温度控制偏高导致钛析出物粗化是造成性能不合的主要原因。通过成分优化及工艺制度调整，实现了碳化钛的充分固溶，提高了钛析出强化效果，解决了力学性能不合的问题。

Effect of titanium strengthening on mechanical properties of 700MPa grade high strength weathering steel and its improvement

Against the low yield strength and tensile strength of 700MPa grade high strength weathering steel in 10mm and 14mm thickness specification, the microstructure was studied by means of metallurgical microscope and scanning electron microscope, the controlling situations during the steel-making and hot rolling process were checked, the effects of TiC solid solution and precipitation strengthening on mechanical properties were researched. The results showed that insufficiently implemented heating technology led to TiC incompletely solid solution and high cooling temperature led to Titanium precipitates alligatoring, which were the main reasons resulted in the unqualified mechanical properties. By means of chemical composition optimization and process technology adjustment, the fully solid solution of TiC was realized, the effect of Titanium precipitation strengthening was improved and the problem of unqualified mechanical properties was solved.