|
|
|
| EFFECTS OF OVERLOADING ON CORROSION FATIGUE CRACK GROWTH FOR ULTRA-HIGH STRENGTH STEEL-Ⅰ. QUANTITATIVE MODEL AND PREDICTION |
| Lu Minxu; Zheng Xiulin (Northwestern Polytechnical University) |
|
|
|
|
Abstract A quantitative descriptive model was developed theoretically of the effects of overloading on corrosion fatigue crack growth (CFCG) of hydrogen embrittlement type. This is based on the comprehensive combination of the Willenborg' overloading residual stress field model with the following knowledge of the process of CFCG: crack tip surface deformation kinetics, the crack tip surface hydrogen evolution kinetics, and the hydrogen diffusion kinetics and thermodynamics in crack tip metal matriX interior. A series of criteria and equations were correspondingly deduced. Furthermore, this model has been used to predict the effects of overloading on CFCG. The results suggest that for ultra-high strength steel, if crack length, ad, grown during the interval of two overloading cycles, were smaller than the difference betwere the overloading plastic region size, rpOL,and the constant loading plastic region size, rpCLA,i. e. ad << rpOL-rpCLA,the retardation effect of overloading on CFCG would be more intensive in 3.5%NaCl solution than in air;on the contrary, if ap≥rpOL-rpCLA, the acceleration effect of overloading on CFCG would occur. It is note-worthy that the overloading acceleration effect does not occur for fatigue in air. The correctness and usefulness of these predicted results have been favourably proved by the macroscopic experimental laws and microscopic fractographic characteristics, the details of which will by presented in the next paper.
|
|
Received: 25 June 1994
|
| 1ZuidemaJ,MensePJM．EdwardsAH．Eng．Fract．Mech．．1987,26(6):927-9352藏启山,刘慷,柯伟,郑宇礼．中国腐蚀与防护学报,1989,9(3):169-1743钱友荣,何向东．金属学报,1989,25(6):A444-A4474NibberingJJW．CorrosSci,1983,23(6):645-6625蒋祖国主编．飞机结构腐蚀疲劳,北京:航空工业出版社,1992,98-1016DillHD,SaffCR．高泽迥译．环境-载荷复合作用对裂纹扩展的影响,航空学报杂志社,19917HangLMater．SciEng．,1988,A103(1):191-2058路民旭,郑修麟．中国腐蚀气防护学报,1994,14(2):9WillenborgJ．EngleRM,WoodHA．ACrackGrowthPredictionModelUsinganEffectiveConcept．Rep．AFFDL-TR-71-1．(USAirForceFlightDynamics);197110韩光炜,宁余九．中国腐蚀与防护学报,1991,11(4):297-30811NakasaK,Takai-H．KidoM．Eng．Fract．Mech．,1977;9(5):867-87712路民旭,郑修麟,秦熊浦．中国腐蚀与防护学报,1991,11(3):197-20813TurnbullA,SenzdeSantaMariaM．Metall．Trans．A;1988,19A(7):1795-180614ScottPM,TruswellAE,DruceSG．Corrosion,1984,4(7):350-35715KnottJF．疲劳裂纹扩展模型．In:SmithRAed．顾海澄译．疲劳裂纹扩展-30年来的进展,西安:西安交通大学出版社,1988,19-4416路民旭,刘晓坤,王建军,傅祥炯,郑修麟．航空学报,1993;14(1):A49-A5517肖纪美．应力作用下的金属腐蚀,北京:化学工业出版社,1990,297-29818GerberichWW,ChenYT．Metall．Thans．A,1975,6A(2):271-27819陈永定,余新昌等编译．金属和合金中的氢,北京:冶金工业出版社,1988,299-300 |
| No Suggested Reading articles found! |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
|
