晶粒形态对Ti-Mo钢耐蚀性能的影响  

Effect of grain morphology on corrosion resistance of Ti-Mo steel

作　　者：杨洪波[1] 李昊玥 赵贺然 孙蒙 邵明增[1] 亓伟伟 YANG Hong-bo;LI Hao-yue;ZHAO He-ran;SUN Meng;SHAO Ming-zeng;QI Wei-wei(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：《材料热处理学报》2024年第11期158-166,共9页Transactions of Materials and Heat Treatment

基　　金：陕西省自然科学基础研究计划资助项目(2021JM369);西安建筑科技大学大学生创新创业训练计划项目(S202310703135)。

摘　　要：采用周期浸润腐蚀实验机、光学显微镜(OM)、扫描电镜(SEM)和电子背散射衍射(EBSD)技术等研究了晶粒形态对Ti-Mo微合金钢耐蚀性能的影响规律。结果表明:Ti-Mo微合金钢经600~750℃等温热处理后的显微组织为单相铁素体,耐蚀性能受晶粒尺寸、大角度晶界比例、再结晶程度的影响;晶界和变形组织作为阳极,晶粒作为阴极,不均匀的电化学腐蚀使实验钢的腐蚀电流升高,促进了电偶腐蚀的发生,这是影响Ti-Mo微合金钢腐蚀行为的主要机制;在不损害力学性能的前提下,可通过采取适当增大晶粒尺寸、降低大角度晶界比例、提高再结晶程度的措施,提高Ti-Mo钢的耐蚀性能;在本实验条件下,当等温温度为600℃时,Ti-Mo钢的晶粒尺寸为9.66μm、大角度晶界比例为80.3%、平均错配角为1.99°、腐蚀质量损失率为1.98 g/(m^(2)·h),其耐蚀性能较高。Effect of grain morphology on corrosion resistance of Ti-Mo microalloyed steel was studied using periodic infiltration corrosion testing machine,optical microscope(OM),scanning electron microscopy(SEM)and electron backscatter diffraction(EBSD)technique.The results show that the microstructure of the Ti-Mo microalloyed steel after isothermal heat treatment at 600-750℃is singlephase ferrite,and its corrosion resistance is influenced by grain size,proportion of large angle grain boundaries,and degree of recrystallization.The grain boundary and deformed structure serve as the anode,while the grains serve as the cathode,the uneven electrochemical corrosion increases the corrosion current of the experimental steel,promoting the occurrence of galvanic corrosion,this is the main influencing mechanism of the corrosion behavior of the Ti-Mo microalloyed steel.On the premise of not damaging the mechanical properties,the corrosion resistance of the Ti-Mo steel can be improved by taking measures such as appropriately increasing the grain size,reducing the proportion of large angle grain boundaries,and improving the degree of recrystallization.Under the conditions of this experiment,when the isothermal temperature is 600℃,the grain size of the Ti-Mo steel is 9.66μm,the proportion of large angle grain boundary is 80.3%,the average mismatch angle is 1.99°,and the corrosion mass loss rate is 1.98 g/(m^(2)·h),showing excellent corrosion resistance.

关 键 词：Ti-Mo微合金钢 耐蚀性能 晶粒尺寸 大角度晶界 再结晶程度 

分 类 号：TG142.3[一般工业技术—材料科学与工程]