The high strength low alloy steel Domex 700MC welded joints were prepared by solid wire carbon-dioxide arc welding process. The specimens for fretting wear test were cut from the sound as-welded joints at the weld zone, fusion zone and heat affected zone respectively. The fretting wear tests were carried out, and the morpholgy of the fretted wear scars were observed using SEM. The results show that under the test conditions, the plane surface area of the worn scars of the welded joints varied less, but the worn off volume and the maximum depth of the worn scars at different zone changed largely. The fretting wear properties of the welded joints at different zone were different and the weld zone metal had the best fretting wear properties. On the contacting wear interfaces, there were many micro-cracks which grew and met each other, and then led to the joint metal drop in the form of flakes or particles. The crater formed after metal drop was beneficial for forming new micro-cracks.%采用实芯焊丝CO气体保护焊方法焊接了低合金高强钢Domex 700MC,在无缺陷的焊态接头试样上从焊缝区、熔合区和焊接热影响区中分别截取试样进行微动磨损试验,用SEM观察了磨痕形貌.结果表明:在选定的微动磨损试验参数下,不同部位金属的磨痕面积差异较小,磨损体积和最大磨痕深度差异较大;接头不同部位金属具有不同的微动磨损性能,焊缝中心金属的耐微动磨损性最好;磨损面上存在与滑移方向成不同角度的微裂纹,这些微裂纹扩展、相交后导致金属呈块状或颗粒状脱落,所形成的凹坑有利于新的微裂纹形成.
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