摘要
运用快速多重旋转碾压(FMRR)在室温下使搅拌摩擦焊缝表面发生塑性变形,晶粒在压应力和不同方向切应力的作用下,产生位错的交割和剪切.随着碾压的进行,使得焊缝表面的晶粒细化.结果表明,试样未经碾压前,母材截面的显微硬度在80~90 HV范围内波动,当FMRR处理60 min后,表面的最大硬度达到185 HV左右,随着层深的增加,硬度值逐渐降低.垂直于表面方向,随着到表面的距离逐渐增大,晶粒尺寸逐步增大,直至达到基体晶粒尺寸.同时经过快速多重旋转碾压,细化后样品的表面硬度明显提高,随晶粒细化程度增加,硬度增大.
Fast multiple rotating rolling( FMRR) is used to make friction stir weld surface plastic deformation,under the effects of compressive stress and shear stress in different directions,resulting in the delivery and shear of Grain dislocations.The results show that with the rolling proceeds,the Grain on weld surface become refinement. The hardness of the base metal section within 80 ~ 90 HV range fluctuations before rolling sample,after 60 min FMRR treatment,the maximum surface hardness of about 185 HV,with increasing layer depth,the hardness value is gradually decreased. A direction perpendicular to the surface,with the distance increases from the surface,the grain size is gradually increased until it reaches the matrix grain size.After fast multiple rotating rolling. After fast multiple rotating rolling the surface hardness of the grain-refining sample has been improved significantly. That is,with the increase in the degree of grain refinement,hardness increases.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2017年第2期125-128,共4页
Transactions of The China Welding Institution
基金
南京工程学院大学生科技创新基金资助项目
