湘钢含铝冷镦钢开发及质量控制

Development and Quality Control of Aluminum Killed Cold Heading Steels in Xiangtan Iron and Steel Group Co.,Ltd

采用铁水预处理—顶底复吹转炉—LF精炼—小方坯连铸—铸坯检验—高线/二高线/棒材轧制工艺,成功地开发出XSWRCH6A^XSWRCH35A等中、低碳优质含铝冷镦钢盘条和棒材。生产中严格控制转炉冶炼、LF精炼、连铸和轧制工艺,保证了钢中wS,wP,wA ls,wT.O合格,热轧态组织为铁素体+少量粒状珠光体和粒状贝氏体,铁素体晶粒度评级为8~8.5级。各级别含铝冷镦钢力学性能优良,1/3冷顶锻试验合格率平均为98.6%,1/4冷顶锻试验合格率达到97.7%。

A series of high quality aluminum killed cold heading steel coil and rods from grade XSWRCH6A to XSWRCH 35A are successfully developed by the combined use of hot metal pretreatment, top and bottom combined blown converter, billet concasting, billet test, and high speed wire-rod mill process at Xiangtan Iron and Steel Co. Strictly controlling production technology from converter smelting, LF refining, continuous casting to rolling to guarantee qualified chemical compositions of S, P, Als, T. O, the metallurgical structures under hot rolling state are formed by ferrite with crystal grain 8 - 8.5 grade, a little granular pearlite and bainte. All the classes of aluminum killed cold heading steels boast excellent mechanical properties with the percent of pass by 1/3 cold upsetting test reaching 98.6% and by 1/4 cold upsetting test 97.7%.