Method capable of improving corrosion resistance of stainless steel composite plate welded through carbon steel stud welding

Abstract

The invention discloses a method capable of improving corrosion resistance of a stainless steel composite plate welded through carbon steel stud welding. The method comprises following steps: firstly, a nickel strip (2) with the nickel content larger than 99% is placed on a stainless steel composite plate base material (1); secondly, a welding nail (3) is placed in a clamping device of a welding gun, protection ceramic rings (4) are placed on the stainless steel composite plate base material (1) laid with the nickel strip (2), and the welding nail (3) is inserted into the protection ceramic rings (4) and makes contact with the nickel strip (2); thirdly, a power switch is pressed, the welding nail (3) is automatically lifted, an electric arc is excited, the end of the welding nail (3) and the local surface of the stainless steel composite plate base material (1) are molten, and after the set time reaches, the welding nail (3) is automatically pressed into the stainless steel composite plate base material (1); and after a welding line is cooled, the protection ceramic rings (4) are broken to pieces and cleared way, and welding is completed. According to the method, corrosion resistance and tensile strength of a welding joint are improved, and welding safety is improved.

Description

technical field [0001] The invention relates to the technical field of railway bridge construction, in particular to a method for improving the corrosion resistance of carbon steel stud welding stainless steel composite plates. Background technique [0002] In order to solve the corrosion problem of steel bridges, stainless steel composite plates are used in China to make railway bridge ballast tanks, and M16-M22 welding studs are welded on the stainless steel composite plates to connect the concrete ballast bridge deck with stud welding. [0003] For example, in the utility model patent with the authorized announcement number CN 201344361 Y, a connection structure between carbon steel screws and stainless steel substrates is disclosed, which is manufactured by a stud welding machine. An arc is generated between the surfaces, and when the joint surfaces are melted, pressure is applied rapidly to form a molten joint and complete the welding. [0004] However, in the stud wel...

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Problems solved by technology

[0004] However, in the stud welding process of the above method, due to the difference in thermal physical properties and electromagnetic properties of stainless steel and carbon steel, the temperature of the liquid metal at the edge of the molten pool on both sides of the base metal is different, and the welding time of stud welding is very short. As a result, the fluidity of the metal in the molten pool becomes poor, and the mechanical and electromagnetic stirring effects are relatively weak. Therefore, the molten metal at the edge of the molten pool cannot be fully mixed with the molten filler metal, thus forming an uneven chemical composition. Solidification transition layer of various carbides and oxides, also known as fusion zone

Due to the dilution of the weld metal, a concentration gradient of chromium and nickel is formed near the fusion line. When the content of austenite-forming elements in the weld metal is reduced to a certain value, the austenite-forming elements in the weld fusion zone Insufficient, thus forming unstable austenite, affecting the corrosion resistance of stainless steel

At the same time, under the action of welding stress on the side of the welding stud, martensite, bainite, widmansite and other structures formed around the fusion line become hard and brittle, resulting in a decrease in the tensile strength of the welded joint

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