余热处理生产高强度钢筋性能研究

The Research on the properties of high strength grade reinforced bar by remained heat treatment

利用余热处理技术通过优化控冷工艺控制系统，制定合理的穿水冷却操作规程，生产符合国家标准及英、美、德等先进国家标准的高强度等级建筑钢筋。研究表明，钢筋表面发生淬火、回火转变，根据强度等级的不同，显微组织为回火马氏体或者回火索氏体，芯部为铁素体加珠光体或者铁素体加索氏体、贝氏体等，钢筋具有高强度和良好塑性的理想配合。钢筋经常规焊接后，焊接区域强度下降幅度较大，所以此工艺生产的高强度钢筋更适用于非焊接方式连接。

The controlling system of remained heat treatment technology is optimized, and the proper water cooling regulations are established. The high quality and high strength reinforced bars are produced according to GB, BS, ASTM, DIN, etc. The investigations reveal that quenching-tempering transformation occurs at the surface layer of the reinforced bar produced by remained heat treatment, and the microstructure of the layer is consist of tempered martensite or sorbite. There are ferrite and pearlite, or ferrite and sorbite, bainite, and so on at the center area. The bars possess ideal strength and plastic properties. The strength of the bar will decrease observably by welded .The bar is fit for non-weld joint.