1. Research and Development Center, Wuhan Iron and Steel Co.， Ltd., Wuhan 430080, Hubei, China 2. Quality Inspection Center, Wuhan Iron and Steel Co.， Ltd., Wuhan 430080, Hubei, China
Abstract：The main shaft of 40CrNiMo cladding machine was fractured abnormally in use. In order to find how it happened, the fracture of main shaft was deeply investigated by macroscopical observation, scanning electronic microscope, X- ray energy spectrometer and metallography microscope. The result showed that the main shaft fracture was the corrosion fatigue failure. Due to the poor steel of the main shaft , some etch pits were formed on its surface under the environment medium erosion, which would be developed into the micro cracks under the effect of stress concentration. And the micro cracks expanded under circulation working stress, which eventually led to the fatigue fracture of the main shaft. It could be resolved by promoting the quality of steel, reducing the corrosivity of environment and improving the heat treatment process and other measures.
2016, Vol. 26 
