热轧N500B钢耐寒带肋钢筋的研制

Development of Hot-rolled Cold-resistant Ribbed Bar of N500B Steel

试验研究了热轧N500B钢耐寒带肋钢筋的生产工艺。直径20 mm的热轧N500B钢耐寒带肋钢筋的生产工艺为UHP电弧炉熔炼→LF炉精炼→VD处理→小方坯连铸→加热→轧制→快速冷却→空冷。该N500B钢带肋钢筋的表层显微组织为粒状贝氏体加少量板条状贝氏体,心部显微组织为铁素体加粒状贝氏体及少量马氏体和极少量珠光体。试验结果表明,热轧N500B钢耐寒带肋钢筋的成分设计和冶炼、轧制工艺均是合理的,其常温及-170℃低温力学性能均符合要求。

Production technology for hot-olled cold-esistant ribbed bar made of N500B steel was experimentally studied.The production processes for this bar20mm in diameter was comprised of UHP electric arc furnace melting,LF furnace refining,VD treating,continuous casting of small billet,heating,rolling,rapid cooling,and air-cooling.The microstructures in case of the ribbed bar were granular bainite and a small amount of lath bainite,and that in the core were ferrite,granular bainite,a small amount of martensite and extremely small amount of pearlite.It was seen from experimental results that the composition design,melting and hot-rolling processes were all reasonable for the hot-olled cold-esistant N500B steel ribbed bar,with its mechanical properties at both room temperature and low temperature of-170℃onforming with the requirements.