电力铁塔紧固件用SWRCH25K冷镦钢盘条的开发及应用

Development and application of SWRCH25K cold heading steel wire rod for electric-tower fastener

介绍SWRCH25K冷镦钢热轧盘条的开发过程。给出盘条生产工艺的控制要点:(1)碳含量按中限控制,硅含量按中下限控制。(2)冶炼采用高拉碳技术高碳低磷出钢,喂Fe-Ca线进行夹杂物变性处理,提高钢质纯净度。(3)连铸采用全保护浇注、严格控制过热度,保持拉速稳定,二冷采用弱冷配水及电磁搅拌技术,保证铸坯质量。(4)采用控制轧制和控制冷却技术,优化工艺及设备,加强过程控制管理。成品螺栓抗拉强度670～680 MPa,延伸率9%～12%,心部硬度为92.2～96 HRB,可满足电力铁塔用6.8级紧固件的需求,并且模具损耗大大降低。

To introduce the development process of SWRCH25K cold heading steel hot-rolled wire rod. To give the control points of wire rod production technology ： （ 1 ） carbon contents control by middle level, and silicon contents control by below average level. （2） to smelt by using high-carbon technology to produce high-carbon low-phosphorous steel, and make in- clusion modification for Fe - Ca line and improve steel purity. （3） continous casting uses full protection casting and to con- trol degree of superheat, keep steady drawing. The second cooling to use low cooling water and EMS techonology to ensure casting blank quality. （4） to use rolling control and cooling control technology, and optimize technology and equipment, and enhance process control management. Finished bolt＇s tensile strength is 670 -690 MPa, elongation rate is 9% - 12%, the hardness of the heart is 92. 2 - 96 HRB, the loss of die decreased largely, which can satisfy the needs of 6. 8 level fastener for electric-tower.