The Development Of High-hardness And Wear-resisting Electrode

Many mechanical parts are made of metal material, they will have cracks, wearing or breakage after long-time working in the complex and severe rugged environment, even lead to scrap the machines when the defects are severe, so these defective workpiece need welding renovation. Being an important branch of the welding field, the build-up welding which is used to rise the working life of equipments and parts or only recover the parts dimension size, is widespread available in the machinery. In this paper, I studied a high hardness and high wearing build-up welding rod by controlling the martensitic phase transformation temperature(Ms), which also calls low transformation temperature welding electrode, then systematically test and analyze the weld performance of build-up-welding and butt-welding.In the paper, I systematically studied that the low transformation temperature welding rod and the method, technique, mechanics, adaptability and the influencing factors of the welded hardness, wear-resisting property and crack resistance. Designed the electrode, analyze the transformation stress generation and the influence regularity of transformation initiation temperature to welded residual stress. In the experiment, it was tested that how the electrode increased the welded hardness, wear-resisting property and crack resistance in the approximate actual environment. And do my best to ensure the electrode build-up welding conditions.Get the best welding electrode by adjusting the carbon alloy content of the coating. No need to preheating treatment before welding and no cracks after welding. The Ms is 254℃. The weld hardness is tested to be HRC54, which is much higher than the base metal. The weld is 33.6 times the wearing strength of the base metal. The metallurgical structure was analyzed to be acicular martensite and residual austenite. Weld the 45steel in butt welding with these new electrode,then tested that the transverse and longitudinal residual stress were both little compression stress. Test and analyze the welded joint impact-toughness, deposited metal Erichsen.