钒微合金化和控轧控冷技术在高强度弹簧钢中的应用.pdfVIP

1钒微合金化和控轧控冷技术在高强度弹簧钢中的应用 崔 娟 刘振民 韩伟旗 (邢台钢铁有限责任公司，河北省线材工程技术研究中心, 邢台 054027) 摘 要 本文通过热模拟试验，采用光学、电子显微技术和力学分析等方法，系统研究了不同控轧控冷工艺对含钒 弹簧钢钒碳氮化物的析出行为、显微组织和力学性能的影响规律，提出了生产含钒高强度弹簧钢最佳的控轧控冷工 艺参数。试验结果表明，在Si-Cr-V系弹簧钢化学成分的基础上，通过控轧控冷工艺参数的优化可以获得组织性能 理想的热轧材成品，其索氏体含量达到了 90 ％，Rm ＝1250MPa，Rp0.2 ＝850MPa，A ＝16.7%，Z ＝37.1% 。 关键词 控轧控冷 钒微合金化 组织性能 弹簧钢 Application of Vanadium Microalloying and Controlled Rolling and Cooling Process on High-strength Spring Steel Cui Juan Liu Zhenmin Han Weiqi (Xingtai Iron Steel Corp.,Ltd., Heibei Engineering Research Center of Steel Wire, XingTai, 054027) Abstract By using simulated rolling process, optical and electron microscopy technique, mechanical analysis etc, the effect of different controlled rolling and cooling processes on the precipitating behavior of vanadium carbonitride, microstructures and properties on spring steel microalloyed with V was studied. The optimal controlled rolling and cooling schedules was proposed. The results showed that the microstructures and properties of hot-rolling rods of Si-Cr-V spring steels will be improved by optimal technologies of controlled rolling and cooling. The content of sorbite is 90%, and the tensile strength is advanced to 1200MPa, the yield strength to 850MPa, the elongation to 16.7%, the reduction of area to 37.1%. Key words controlled rolling and cooling, vanadium microalloying, microstructures and properties, spring steel 1 引言 当今关于微合金元素在热变形奥氏体及随后控冷过程中固溶与沉淀规律的大量研究，促进了高强度微合 金化钢控轧控冷技术的发展与广泛应用。随着汽车轻量化和高速化的发展，汽车用悬挂簧的疲劳性能及抗弹 减性能要求越来越高[1~3] 。为进一步提高高强度弹簧钢的综合力学性能，在中碳弹簧钢中加入微量的钒元素， 通过控轧控冷工艺参数的优化，充分发挥钒碳氮化物与微观组织的相互作用，实现析出强化、细晶强化和组 [4~6] 织均匀化的精确控制，获得理想的组织性能 。 由于中碳弹簧钢合金化的特点，其热轧材的组织基本为“索氏体＋珠光体＋少量的先共析铁素体” 。弹簧 钢热轧材组