摘要
采用激光冲击强化(LSP)技术在300M钢表层制备梯度纳米结构,并借助三维表面形貌仪、扫描电镜(SEM)、透射电镜(TEM)、X射线衍射仪(XRD)、纳米压痕仪及拉伸试验机对300M钢不同脉冲能量LSP处理后的微观组织演变和力学性能变化进行表征。结果表明,300M钢经LSP处理后表层形成梯度纳米结构,随着脉冲能量的增加,表层晶粒尺寸从15 nm(3J)细化至10 nm(7J)左右,晶粒出现非晶化;同时,次表层组织中形成了大量位错缠结及形变孪晶等亚结构缺陷,且随着脉冲能量的增加位错密度急剧增高,同时形变孪晶数量也随之增多。LSP后300M钢表层纳米压痕硬度得到显著提高,且随着脉冲能量的增加而增加;强度和塑性得到一定程度的改善,断口形貌由典型的韧性断裂转变为韧-脆混合型断裂。
The gradient nanostructures are prepared on the surface of 300M steel by laser shock processing(LSP).The microstructure and mechanical properties of 300M steels subjected to LSP with different pulse energies are characterized by three-dimensional surface profilometer,scanning electron microscope(SEM),transmission electron microscope(TEM),X-ray diffractometer(XRD),nano-indentation instrument and tensile tester.The results show that the gradient nanostructures are formed on the surface of 300M steel after LSP treatment,that the grain size of the surface layer is refined from 15 nm(3 J)to about 10 nm(7 J)with the increase of the pulse energy,and that the grains turn to be amorphous.Meanwhile,a large number of crystal substructure defects such as dislocation tangles and mechanical twins are formed in the subsurface structure.With the increase of pulse energy,the dislocation density increases sharply and the number of mechanical twins increases.The nano-indentation hardness of 300M steel is significantly improved after LSP and increases with increasing pulse energy.The corresponding strength and plasticity are improved to some extent and the fracture morphology changes from typical ductile fracture to ductile-brittle mixed fracture.
作者
马云飞
王迎辉
熊毅
栾泽伟
舒康豪
吕威
MA Yunfei;WANG Yinghui;XIONG Yi;LUAN Zewei;SHU Kanghao;LÜWei(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471000,China;Luoyang Ship Material Research Institute,Luoyang 471023,China)
出处
《材料开发与应用》
CAS
2022年第6期55-62,共8页
Development and Application of Materials
基金
国家自然科学基金项目Nos.U1804146、52111530068
河南省外专引智计划项目HNGD2020009
关键词
300M钢
激光冲击强化
梯度纳米结构
微观组织
力学性能
300M steel
laser shock processing
gradient nanostructure
microstructure
mechanical property
作者简介
马云飞,男,1996年生,硕士研究生,研究方向为先进钢铁材料及其激光表面改性。E-mail:myf234515@163.com
