论文部分内容阅读
深入调查了中国HRB400/400E和HRB500/500E高强度热轧钢筋的质量现状。从不同地区的钢筋生产厂和使用场所取样分析了高强度热轧钢筋成分、宏观金相、微观组织和截面硬度。按照钢筋化学成分范围,目前中国高强度热轧钢筋可归为4类,即含钒钢筋、低钒钢筋(<0.02%钒)、20MnSi钢筋和C-Mn钢筋。宏观金相和微观组织观察结果表明,只有含钒钢筋能完全满足热轧钢筋的组织要求,其他3类钢筋截面基圆外围均出现非铁素体-珠光体组织的表面硬化层。基于高强度热轧钢筋的质量分析结果,提出了热轧带肋钢筋国家标准GB 1499.2—2007的修订建议。
In-depth investigation of China HRB400 / 400E and HRB500 / 500E high-strength hot-rolled steel quality status quo. High-strength hot-rolled steel bar components, macro-metallurgies, microstructure and cross-section hardness were sampled from steel bar production sites and usage sites in different regions. According to the scope of the chemical composition of the rebar, at present, China’s high-strength hot-rolled rebar can be classified into four categories, namely vanadium-containing rebar, low vanadium rebar (<0.02% vanadium), 20MnSi rebar and C-Mn rebar. The results of macro-metallography and microstructure show that only the vanadium-containing steel bars can completely meet the microstructure requirements of hot-rolled steel bars, and the surface hardening layer of non-ferrite-pearlite structure appears in the periphery of the basic circle of the other three types of steel bars. Based on the quality analysis results of high strength hot rolled steel bar, a revised proposal of national standard GB 1499.2-2007 for hot rolled ribbed steel bar was proposed.