The Development Of Low Transformation Temperature Surfacing Welding Electrode

The consumption of iron and steel materials is larger with the fast development of Mechanical industry. The damage of Mechanical units is always caused by fatigue failure, which is induced by the wearing of small parts of the units. The fixing of surfacing welding not only can prolong life and save the costs of manufacturing, but also can improve combined properties. Therefore, the studies of these welding materials, which can prevent from cracking and have high wear-resistance, have remarkable benefits in society and economy.Based on the principal of the volume expansion during the cooling that steel materials transform from austenite to martensite, and the affecting factors of wearing resistance, and the analysis of the influence of chemical elements on the Ms and combined properties, the low transformation temperature surfacing welding electrode has been designed.The residual stress around welded seam is residual compression stress both in longitudinal and transverse by means of residual stress testing, so the tendency of cracking was remarkably reduced. Besides, the paper made deeply analysis on the relationship between transformation temperature of martensite and residual stress through the testing of transformation temperature of martensite.Contrast to base metal (steel 45#), the welded joints made by designed electrode have better wear resistance property. The paper provides an analysis of the microstructures and chemical contents with optical microscope scanning electron microscope, discussed the influence of microstructures,hardness and chemical contents on the material wear-resistance, the properties of electrode has been optimized.