钛含量对Ti-Mo微合金钢组织及性能的影响  

Microstructure and Properties of Ti-Mo Microalloyed Steel with Different Ti Contents

作　　者：杨洪波[1] 赵贺然 孙佳通 王豪 邵明增[1] 亓伟伟 Yang Hongbo;Zhao Heran;Sun Jiatong;Wang Hao;Shao Mingzeng;Qi Weiwei(School of Metallurgical Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;Technical Center,Laiwu Branch of Shandong Iron and Steel Co.,Ltd.,Jinan 271100,China)

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055 [2]山东钢铁股份有限公司莱芜分公司技术中心,山东济南271100

出　　处：《稀有金属》2024年第11期1543-1551,共9页Chinese Journal of Rare Metals

基　　金：陕西省自然科学基础研究计划项目(2021JM369)资助

摘　　要：以不同Ti含量的Ti-Mo微合金钢为研究对象,利用光学显微镜(OM)、拉伸试验机、冲击试验机测试了实验钢的微观组织形貌及力学性能参数,分析了Ti含量对微观组织、抗拉强度、屈服强度、延伸率、冲击韧性的影响规律,计算了实验钢的强化量,阐明了强化机制,并探讨了屈强比的影响因素,为Ti-Mo微合金钢力学性能的进一步优化提供参考。结果表明:Ti含量在0.012%~0.16%时,Ti含量的增加使实验钢的抗拉强度及屈服强度增大,铁素体晶粒尺寸逐渐减小,塑韧性能逐渐降低后稳定下来;Ti含量升高到0.21%时,铁素体晶粒尺寸变大,实验钢强度降低。当Ti含量在0~0.026%时,实验钢强化方式以细晶强化和固溶强化为主;当Ti含量在0.04%~0.21%时,实验钢强化方式以细晶强化和析出强化为主,且随着Ti含量的增加析出强化量逐渐增大。强化方式是影响屈强比的因素之一,固溶强化可以降低屈强比,细晶强化和析出强化会增大屈强比;另一影响因素是钢中软硬相比例,软相影响屈服强度,硬相影响抗拉强度,为了使实验钢在高强度的同时获得较低的屈强比,可以适当控制钢中铁素体与贝氏体比例。综合考虑,当Ti含量在0.11%时,可获得屈服强度为482 MPa,抗拉强度为647 MPa,屈强比为0.7456的综合力学性能较优异的高强钢。Microalloyed steel is based on low-carbon steel or ultra-low-carbon steel.By adding small amount alloying elements,a large number of nano-scale precipitated particles are formed inside the steel during the austenite/ferrite transformation,which enhances the mechanical properties of the steel.As a microalloying element widely used in steel,Ti is easy to form TiC and TiN with carbon and nitrogen.TiC and TiN particles in steel can play a role in grain refinement and precipitation strengthening by inhibiting grain growth,pinning dislocations at high temperatures or during rolling.At the same time,the price of Ti element is low,which can reduce the cost of materials and improve economic benefits.The addition of Mo element to Ti microalloyed steel can form(Ti,Mo)C particles inside the steel,which has an excellent ability to resist grain coarsening.Meanwhile,it can inhibit the nucleation and growth of TiC particles,and promote precipitation strengthening and fine grain strengthening.Ti-Mo microalloyed steel has attracted wide attention due to its high strength,good weldability,and formability,and has a wide field of applications with good prospects.However,in a state of high strength,the problem of a high yield ratio remains to be solved.Therefore,reducing the yield ratio is of great significance to improve the formability of the material and the safety performance during use.In this paper,eight kinds of Ti-Mo microalloyed steels with different Ti contents in a hot rolled state were taken as the research object.The microstructure and mechanical properties of the steels were tested by optical microscope(OM),tensile testing machine and impact tester.The effects of Ti content on the microstructure,tensile strength,yield strength,elongation,and impact toughness of the tested steels were systematically analyzed,based on the observation results and test data.Using the calculation formula of the comprehensive strengthening mechanism of steel,combined with the solid solubility amount of each element,ferrite grain size,effective

关 键 词：TI含量 Ti-Mo微合金钢 延伸率 强化 屈强比 

分 类 号：TG142.13[一般工业技术—材料科学与工程]