铌微合金化控冷HRB400钢筋的试制

Trial Production of HRB400 Ribbed Bars by Nb-Microalloyed and Controlled Cooling

将Nb微合金化技术和控制轧制、控制冷却技术进行综合应用,开发出了具有成本优势的HRB400钢筋。介绍了产品开发的技术思路、成分设计、生产工艺路线、冶炼和连铸工艺和轧制工艺。在20 MnSi成分的基础上,添加0.008%~0.028%的Nb,可生产单线轧制的φ12~φ25 mm HRB400钢筋;添加0.021%~0.036%的Nb、0.010%~0.027%的Ti,可生产单线轧制的φ28~φ32 mm和切分轧制的φ16~φ20 mm HRB400钢筋。轧制时钢筋上冷床温度宜控制为810~870℃。钢筋的组织为铁素体＋珠光体或铁素体＋珠光体＋少量贝氏体,表面无自回火组织。

HRB400 ribbed bar with low cost advantage was developed by synthetic using technology of Nb-microalloyed and controlled rolling,controlled cooling.Technologic thought,chemical composition design,produce route,smelting process,continuous cast process and rolling process were recommended in this paper.12～25mm HRB400 ribbed bar could be mongline rolled,with 0.008%～0.028% Nb in it;28～32mm HRB400 ribbed bar could be mongline rolled,16～20mm HRB400 ribbed bar could be slit rolled,adding 0.021%～0.036% Nb and 0.010%～0.027% Ti into it,in the base of chemical composition of 20MnSi.Bar temperature on colling bed should be controlled in the range of 810~870℃ at the time of rolling.Microstructure of ribbed bar was F＋P,or F＋P＋B（small）.There was not self tempered structure on its surface.