摘要
针对HRB500E直条钢筋产品强屈比不合格率较高的现象,利用火花直读光谱仪、金相显微镜、熔融—热导法等检测手段,剖析了HRB500E直条钢筋强屈比不合格的主要原因,并提出了相应的改善措施。结果表明,与合格HRB500E产品相比,不合格HRB500E产品在化学成分、金相组织、晶粒度、夹杂物等方面均无明显差异,但其N元素含量约为1.46×10^(-4),显著高于合格HRB500E产品中N元素的含量(9.94×10^(-5)),故推测出N元素含量高是HRB500E产品不合格的主要原因。通过利用V-Fe合金代替部分V-N合金以减少钢水中N元素的来源,同时优化精炼工艺操作、保护浇铸、调整开浇炉铸坯发坯方式等措施,将HRB500E产品中N元素含量降低至9.00×10^(-5)~1.20×10^(-4)。既保证了N元素对HRB500E产品力学性能的强化作用,同时又使HRB500E产品强屈比达到国家标准要求。
Aimed at the unqualified HRB500E with a low ratio of tensile strength and yield strength,the unqualified HRB500E material was analyzed by the chemical composition,metallographic structure,metallographic inclusion,and N,H and O elements.The results show that compared with qualified HRB500E products,unqualified HRB500E products have no obvious differences in chemical composition,microstructure,grain size,inclusions and other aspects,but the content of N element is about 1.46×10^(-4),which is significantly higher than qualified HRB500E products(9.9×10^(-5)),the high content of N was the main reason for the unqualified HRB500E.By replacing some vanadium-nitrogen alloys with vanadium-iron alloys to reduce the use of vanadium-nitrogen alloys,optimizing refining process operations and protecting pouring,and adjusting the method of casting billets in the open-casting furnace,the content of N elements in steel can be effectively reduced to 9.00×10^(-5)~1.20×10^(-4).This not only ensures the strengthening effect of the N element on the mechanical properties,but also helps the ratio of tensile strength and yield strength of HRB500E to meet the requirements of the national standard in China.
作者
黄乐
刘凯
HUANG Le;LIU Kai(Yangchun New Steel Co.,Ltd.,Yangjiang 529629,Guangdong,China)
出处
《江西冶金》
2022年第6期96-100,共5页
Jiangxi Metallurgy
关键词
HRB500E
微合金化
屈服强度
强屈比
HRB500E
microalloyed
yield strength
ratio of tensile strength and yield strength
