Nb、V微合金化9.8级高强韧非调质冷镦钢盘条的研发  

Development of niobium-vanadium microalloyed 9.8 grade high-strength, high-toughness non-quenched and tempered cold heading steel wire rod

作　　者：张晓瑞[1] 汪开忠[1] 于同仁[1] 王文军 姜婷[1] ZHANG Xiaorui;WANG Kaizhong;YU Tongren;WANG Wenjun;JIANG Ting(Technical Center,Maanshan Iron and Steel Co.,Ltd.,Maanshan 243000,China)

机构地区：[1]马鞍山钢铁股份有限公司技术中心,安徽马鞍山243000

出　　处：《轧钢》2022年第1期115-119,共5页Steel Rolling

摘　　要：针对高强韧9.8级非调质冷镦钢盘条用于生产变形量较大汽车紧固件产品及降低模具损耗的需求,在原MFT8非调质冷镦钢盘条化学成分设计的基础上,采用Nb、V复合微合金化,同时对C、Si、Mn等元素含量进行微调,并通过控制w(V)/w(N),保证盘条的强韧性;通过控制w(Al)/w(N),保证盘条冷加工塑性变形后的应变时效性能;再结合线材冷拔加工所产生的鲍辛格效应,保证最终产品的强度和塑韧性。采用低温轧制+控轧控冷工艺,充分发挥弥散细小碳氮化物的析出强化和沉淀强化作用,在提高盘条强度的同时塑韧性不降低,获得了具有优异冷加工性能的高强韧非调质冷镦钢盘条。热轧盘条无需经过球化退火+调质处理即可直接拉拔冷镦成形,可用于制作长杆法兰螺栓等变形量较大的9.8级高强紧固件。In response to the demand for high strength and toughness 9.8 grade non-quenched and tempered cold heading steel wire rod for the production of large deformation automotive fastener products and reduced mold loss, based on the chemical composition of the original MFT8 non-quenched and tempered cold heading steel wire rod, the niobium-vanadium composite microalloying was used, and the C, Si, Mn and other elements were fine-tuned. By controlling w(V)/w(N), the strength and toughness of the wire rod was ensured, and by controlling w(Al)/w(N), the strain aging performance of the wire rod after cold working plastic deformation was ensured. Combined with the Bauschinger effect produced by cold drawing of the wire rod, the strength and plastic toughness of the final products were ensured. Low temperature rolling, controlled rolling and controlled cooling process were adopted to give full play to the precipitation strengthening effects of dispersed fine carbonitrides. While improving the strength of the wire rod, the plastic toughness was not reduced, and the high strength and toughness of non-quenched and tempered cold heading steel wire rod with excellent cold working properties was obtained. This wire rod could be directly drawn and cold heading without undergoing spheroidizing annealing + quenching and tempering treatment. It could be used to produce 9.8 grade high-strength fasteners with large deformation such as long rod flange bolts.

关 键 词：非调质冷镦钢 盘条 高强韧性 Nb、V微合金化 控轧控冷 析出强化 低成本 

分 类 号：TG335.1[金属学及工艺—金属压力加工]