Welding method for increasing surface hardness of capping bead of wear resistant steel plate

Abstract

The invention discloses a welding method for increasing the surface hardness of a capping bead of a wear resistant steel plate. A high-strength wear resistant steel plate of which the hardness grade is HB360 to HB450 is adopted, the thickness of the high-strength wear resistant steel plate is 16 to 80 mm, a welding wire ER69-G of which the tensile strength Rm is greater than or equal to 690 MPa and argon-rich mixed gas shielded welding are adopted to perform backing welding and filling welding on the interior of a weld groove of a wear resistant steel member, when the capping bead is welded, awear resistant alloy wire is added into the groove, then the capping bead is welded, the fusion of a welded joint is good, and no welding defect exists in the welding seam junction of a capping layerand a packing layer. The welding wire does not need to be replaced in a welding process, only the wear resistant alloy wire is added when a welding seam of the capping layer is welded, and the manufacturing process is relatively simple. According to the process measure, the welded joint of the wear resistant steel member has good comprehensive mechanical properties, and the wear resistant alloy wire is added to the capping bead, so that the hardness of the capping bead reaches more than HRC35, the surface weld metal has high wear resistance, the wear resistant steel member is prevented from failing due to the wear of the welding seam, and the service life of the product is prolonged.

Description

technical field [0001] The invention belongs to the technical field of iron and steel material welding, and in particular relates to a welding method for improving the surface hardness of a wear-resistant steel plate cover weld bead. Background technique [0002] In recent years, with the rapid development of construction machinery, coal mining machinery and other industries, the service life has increasingly become an important factor affecting the production efficiency of modern equipment. As one of the main damage forms of materials, wear is one of the main failure forms of coal mining, mining equipment, various construction machinery and other components, although it does not cause catastrophic damage to steel structure workpieces like fracture and corrosion. The high performance of steel materials is one of the important ways to directly reduce the consumption of steel and improve the service life of steel equipment. High-strength wear-resistant steel is a high-strengt...

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Problems solved by technology

However, the content of carbon in wear-resistant steel is as high as 0.20% to 0.30%, and elements such as Cr, Mo, B, etc. that can improve hardenability are added, and the hardening tendency is relatively large. Since welding is a process of rapid heating and rapid cooling In the unbalanced metallurgical process, it is easy to produce hardened martensite structure after welding. In order to ensure the safe use of wear-resistant steel structures and avoid welding cracks, 50kg-70kg grades are generally selected according to the principle of "low-strength matching". The welding material is used for welding high-strength wear-resistant steel. The problem caused by this is that the hardness of the weld metal is only about HRC20, which is far lower than the hardness of the base metal. During use, it is found that the weld wear of some welded components It is more serious. When the effective size of the weld after wear is less than 3 / 4 of the design weld size, the thinning of the weld will reduce the bearing capacity of the component, which will lead to cracking of the weld and eventually cause the failure of the entire equipment. Therefore, the weld Joint wear is one of the key factors affecting the quality and service life of wear-resistant steel components

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