TAO Zengyi LUO Jiaming Huazhong University of Science and Technology
,
Wuhan
,
China TAO Zengyi
,
Faculty of Metallic Materials
,
Dept.of Mechanical Engineering No.2
,
Huazhong University of Science and Technology
,
Wuhan 430074
,
China
金属学报(英文版)
The influence of laser surface melting and induction hardening on the surface structure,con- tact fatigue life and failure behaviour of the nodular cast iron has been investigated.The con- tact fatigue life can be improved by both laser treatment and induction hardening,but the fail- ure process and type are different from each other.The former is due to lumpy and deep spal- ling caused by crack propagation between the quenching zone and the substrate,and the latter is due to nubby and surface flaking caused by the oil wedged action into surface cracks.
关键词:
surface hardening
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null
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XIAO Jichuang FANG Jianneng South China University of Technology
,
Guangzhou
,
China XIAO Jichuang Associate Professor
,
Dept.of Mechanical Engineering No.2
,
South China University of Technology
,
Guangzhou 510641
,
China
金属学报(英文版)
An investigation was made of the influence of Zr additive on the high temperature phase trans- formations,martensitic forward/reverse transformations,and shape memory effect of Cu-Zn-Al base alloys by means of differential scanning calorimetry(DSC),X-ray diffraction and TEM.It was found that an addition of 0.35 wt-% Zn could effectively inhibit the precipitation of α and γ phases and hence promote the order-martensitic transformations β_2→DO_3→18RM,thus resulting in a minimum activation energy of the martensitic trans- formation and narrow temperature ranges(M_s-M_f)and(A_s-A_f);the alloy so obtained pos- sessed smooth and mobile martensite intervariant interfaces,therefore showing the best shape memory effect.
关键词:
Cu-Zn-Al alloy
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null
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null
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Liu Zhengyi Fu Jian Zhuang Yuzhi South China University of Technology
,
Guangzhou
,
China Correspondent:LIU Zhengyi professor
,
Dept.of Mechanical Engineering No.2
,
South China University of Technology
,
Guangzhou
,
China
金属学报(英文版)
The nature of“white layer”found in 55SiMnMo steel subjected to friction test has been stu- died using TEM,SEM,X-ray diffraction and EPMA techniques.It is shown that the struc- ture of the“white laver”on the rubbing surface is duplex,consisting of a special martensite and some austenite.This layer may be 25—50 μm thick.It is ultrafine,with grain diametric approximately 30 nm.Its micro-hardness may be as high as Hm 1500 and is capable of cut- ting glass.It has superb corrosion resistance and resists tempering.Its mierostructure and hardness undergo changes only when the steel is tempered above 500℃.
关键词:
friction
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null
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