【摘要】 对三种不同基材状态的45~3钢经表面火焰喷焊Ni60后的疲劳性能及腐蚀疲劳性能变化的研究,表明强度高的调质态基材喷焊后的疲劳极限下降7%,而正火态和轧态基材喷焊后疲劳极限提高14%。当有3.5%NaCl腐蚀介质存在时,不管基材强度高或低,表面喷焊都使材料的腐蚀疲劳强度(10~7寿命)提高30%以上。文中通过断口金相分析阐明喷焊后基材表面组织结构变化及其对疲劳裂纹形成及扩展的影响,讨论了Ni60喷焊层在腐蚀疲劳过程的行为,为喷焊工艺在工业中的应用提供了依据。更多还原

【Abstract】 The effects of coating Ni60 on the surface of fatigue specimens of tempered, normalized or rolled C45 steel by flame spraying and remelting on the fatigue life in air and on the corrosion fatigue life in 3.5% NaCl solution have been studied. The results show that: Ni60 coating will reduce the fatigue limit in air about 7% for tempered matrix and increase about 145% for normalized and rolled matrixes, but increase the corrosion fatigue strength of 10~7 lifetimes over 30% for all matrixes. By fractographic analysis the process of fatigue fracture of thermally coated specimens and the corrosion fatigue behaviour of surface coating were studied. It is indicated that the microstructure and strength of the coating and bonding have their direct effects on the fatigue crack initiation and propagation.更多还原