CHEN Wenzhe QIAN Kuangwu FuZhou University
,
Fuzhou
,
Fujian
,
China Lecturer
,
Dept.of Mechanical Engineering
,
Fuzhou University
,
Fuzhou
,
Fujian
,
China
金属学报(英文版)
The effect of various dynamic strain aging(DSA)pre-treatment processes on pure bending fatigue strength of an 18-8 austenitic stainless steel was investigated.The results show that DSA pre-treatment processes increase remarkably the fatigue strength and the strengthening effects increase with increasing pre-strain temperature and pre-strain.The fatigue limit of specimens pre-treated by DSA is 87% higher than that by solution treatment,and 20% high- er than that by cold-working.TEM observations show that the uniform and stable dislocation networks with high density formed after DSA pre-treatment,which suppress effectively the initiation and propugation of fatigue cracks and increase the fatigue strength of materials.
关键词:
dynamic strain aging(DSA)
,
null
,
null
PENG Kaiping CHEN Wenzhe OIAN Kuangwu Fuzhou University
,
Fuzhou
,
China teaching assistant
,
Department of Mechanical Engineering
,
Fuzhou University
,
Fuzhou 350002
,
China
金属学报(英文版)
Studies were made of the symmetric tensile-compressive low cycle fatigue behaviour and the influence of dynamic strain aging(DSA)pre-treatment of 18-8 austenitic stainless steel. Within the testing amplitude range of strain.±0.5 % to±1.5 %,the three processes of cyclic hardening,cyclic saturation and cyclic softening were observed.In the same amplitude of strain,the peak stress of the samples pre-treated by DSA is higher than that of solid-solu- tion and cold working pre-treatment,but no remarkable differences of the fatigue lives of them were found.TEM observation shows that the uniform and stable dislocation networks with high density form after DSA pre-treatment,which increases the cyclic peak stress.The cyclic softening results from the low dislocation density and elongated cell structure with low energy.
关键词:
18-8 austenitic stainless steel
,
null
,
null