Fretting Wear Property of Domex 700MC Welded Joints

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.