材料期刊网

INVESTIGATION OF INFLUENCE OF HYDROGEN ATTACK ON FATIGUE PROPERTIES OF PRESSURE VESSEL STEELS

J.L. Li , K.F. Wang , J. Li , Z.M. Yao and W. Ke(Fushun Petroleum Institute , Fushun 113001 , China)(Department of Chemical Engineering , Zhejiang University , Hangzhou 310027 , China)(Institute of Corrosion and Protection of Metals , The Chinese Academy of Sciences , Shengyang 110015 , China)

金属学报(英文版)

Influence of hydrogen attack on mechanical and fatigue properties of 1020, 15CrMo and 2.25Cr-1Mo steels has been studied, which were exposed to gaseous hydrogen at pressure of 18MPa and 300-480℃ for up to 480h. The results of fatigue test showed that hydrogen attack (HA) resulted in an obvious change in fatigue properties of 1020 and 15CrMo steels, however, 2.25Cr-1Mo steel showed a lower susceptibility to hydrogen attack due to the addition of Cr and Mo. Fatigue crack behaviour for 1020 steel is attributed to hydrogen attack damage and the crack closure induced by the rough cracking surface, which lead to a valley on △Kth～HA% plot. The change in the fatigue behaviour of 15CrMo steel is possibly caused by severe surface decarburization.

关键词: hydrogen attack , null , null , null

STUDY ON FATIGUE DAMAGE BELOW THE FATIGUE LIMIT AND THE COAXING EFFECTS

WU Zhixue , LU Wenge and XU Hao1)(Fushun Petroleum institute , Fushun 113001 , China)2)(State Key Laboratory for Fatigue and Fracture of Materials , Institute of Metal Research , ChineseAcademy of Sciences , Shenyang 110015 , China)3)(Institute of Mechanical Engineering , Northeastern University , Shenyang 110006 , China)Manuscript received 19 July 1995 , in revised form 11 April 1996

金属学报(英文版)

Rotary bending fatigue tests were carried out for smooth specimens of a mediumcarbon steel with two different grain sizes near the fatigue limit. The process of fatigue damagewas observed by replication method, and the effects of grain size,stress level and microstructure on surface damage were studied. The effect of following cycle stress level on the coaxing effects was also discussed. The fatigue limit is the maximum stress at which the short fatigue crack initiates and becomes a non-propagating crack.. The length of non-propagating crack is related to grain sizes and stress level. The coaxing effects disappear when the following stress level is greater than the critical value.

关键词: : fatigue damage , null , null

AN INCREMENTAL METHOD OF X-RAY DIFFRACTION QUANTITATIVE PHASE ANALYSIS OF SAMPLES CONTAINING AMORPHOUS MATERIAL

G. Chu(Department of Applied Chemistry Fushun Petroleum Institute , Fushun 113001 , China)

金属学报(英文版)

A new method for quantitative X-ray diffraction phase analysis of a powder misture has been developed according to Popovic's doping method. The weight fraction of amorphous material in the analysed sample is obtained. For a multicomponent system in which (n-2) pure phases are added into an n-phase compnent sample and theweight fractions of all n phases can be determined by the method. The test results of confirmation agree well with the theory.

关键词: X-ray diffraction , null , null , null

Fushun Steel Plant

TANG Rongde Deputy-chief engineer. Fushun Steel Plant , Liaoning , China.

材料科学技术（英文）

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