LIU Jianchao GUO Yunyi XING Zhongshu SHI Changxu Institute of Metal Research
,
Academia Sinica Shenyang
,
China LIANG Wubiao No.2 Automobile Factory
,
Shiyan
,
Hubei
,
China Professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
110015
,
China
金属学报(英文版)
Effects of 650℃ aging for 1—1000 h on structure and hydrogen embrittlement susceptibility (HES)of steel Cr21Ni6Mn9N have been investigated.The results show that M_(23)C_6 type carbide precipitates at grain boundaries and Cr-depletive region appears beside them during aging.The precipitates grow and connect each other as the aging time prolongs.Meanwhile, the degree of Cr-depletion aggravates first and then recovers gradually while the aging time is very long,i.e.,1000 h.The HES of the steel increases with increasing aging time but does not reduce with the recovery of Cr content at the Cr-depletive region.That implies that the ex- isting of carbides at grain boundaries might be the main reason which promotes the HES of steel during aging.
关键词:
aging
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CHE Chengwei ZHANG Zhiming DONG Xianglin LIU Chengliang Harbin Institute of Technology
,
Harbin
,
150006
,
ChinaInstitute of Metal Research
,
Academia Sinica Shenyang
,
110015
,
China
材料科学技术（英文）
The behaviour of oxidation at elevated tem- peratures and fretting in the laser-alloyed layer of Ti-6Al-4V with the addition of Pr was studied. The results show that the addition of Pr changes the structure of oxide scale of Ti-6Al-4V,controls the short-range diffusion of oxygen to the scale/substrate interface and increases the adhe- sion and ductility of the scale,thus changing the oxidation kinetics and considerably reducing oxidation rate.The analysis of fretting test shows that the existence of high hardness layer in the al- loyed zone,fine dendrites perpendicular to the sur- face of the high hardness layer and the oxide scale produced during fretting at elevated temperatures are all beneficial to the improvement of wear resist- ance.
关键词:
laser modification
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