微氮合金在韶钢热轧钢筋上的应用及研究

Micro-N alloy used for making hot-rolled rebar at Shao Steel

根据韶钢Consteel现有螺纹钢冶炼、轧制工艺,通过分阶段、分规格在韶钢HRB335、HRB400热轧钢筋上试验一种新型的合金材料-微氮合金,结果表明:各项初检性能、时效性能、焊接性能完全符合企业标准要求,钢材的金相组织为:铁素体+珠光体,无回火组织,母材和焊接区金相组织未见有明显变化;钢中较高的氮含量,大量析出高密度且分布尺寸小(5 nm以下)的碳氮化物、氮化物二相粒子是促进钢筋提高强度的关键;吨钢综合生产成本降低10元以上.

Based on the existing rebar steelmaking and rolling process in Shao Steel Consteel, a new type of alloy material, namely the micro-N alloy, was experimented with the hot rolled rebar HRB335 and HRB400. It was found that composed of ferrite ＋ pearlite without tempered （martensite） microstructure, the rebar possessed satisfactory mechanical properties, ageing performance and welding performance in a preliminary inspection, and there were no obvious variations in the micro- structure in hoth the base metal and welded area. The relatively high N content in the steel resulted in a large amount of high density and small sized （5nm below ） two-phase particles composed of carbo-nitride and nitride, which were believed to be responsible for the increase in the rebar strength. The production cost per ton steel was hence reduced by more than 10 RMB through the micro-N Alloy application.