Anti-coating reddening and anti-cracking double-core flux-coated electrode for stainless steel welding

Abstract

The invention belongs to the field of welding materials, and particularly relates to an anti-coating reddening and anti-cracking double-core flux-coated electrode for stainless steel welding. The coreis formed by connecting a solid core with beads and a hollow core with grooves through matching the beads with the grooves, a gap of 0.8-1.2mm is reserved between the solid core and the hollow core,and the outer surface of the hollow core is coated with a coating. The hollow core is made of carbon steel, the volume expansion is small after the hollow core is heated, the generated resistance heatis little, and the phenomena of reddening and cracking of the coating are avoided. The solid core is made of chromium-nickel alloy, the volume expansion is large after the solid core is heated, and much resistance heat is generated. Due to the gap between the solid core and the hollow core, the outer circle of the hollow core does not expand, the heat generated by the solid core can be rapidly dissipated from the gap, and the phenomena of reddening and cracking of the coating are avoided. After the electrode is melted, elements such as nickel and chromium can be uniformly mixed with other parts of a molten pool under the action of electric arc blowing force, and chemical components of a formed weld joint meet the requirements of stainless steel deposited metal.

Description

technical field [0001] The invention belongs to the technical field of welding materials, in particular to a double-weld core coated electrode for stainless steel welding that resists redness and cracking of the drug skin. Background technique [0002] When welding stainless steel materials, traditional stainless steel electrodes are generally used. The welding core of this type of electrode uses stainless steel wire as the welding core, and the outer surface is coated with a coating, which generally has the disadvantage of poor workmanship, mainly because the coating is easy to break out when the electrode is welded to the second half. Red cracking, redness will cause the gas-generating agent in the coating to decompose in advance, and the molten pool will lose the protective atmosphere, increasing the tendency of welded joints to produce pores; at the same time, the beneficial elements passing through the coating will also be burned in advance, and the welding If it is mor...

AI Technical Summary

Problems solved by technology

The disadvantages of this technical solution are: 1) A large number of chromium particles and nickel particles exist in the coating, and the arc is moving. In order to avoid melting defects, the moving speed of the arc should be moderate and not too slow, which will cause The chromium particles and nickel particles cannot all melt into the weld, but part of them melt into the molten pool, and some exist in the welding slag in the form of particles, and the proportion of particles melted in the molten pool and remaining in the slag cannot be predicted and controlled , so its design and manufacture are extremely difficult. On the other hand, due to the gradual decrease in the temperature of the molten pool, the particles dissolved in the molten pool will not melt, but exist in the deposited metal in the form of solid particles, resulting in a decrease in the mechanical properties of the weld. The desired effect cannot be achieved; 2) A large amount of alloying elements chromium and nickel need to be added to the coating. The addition of a large amount of alloying elements in the coating will inevitably lead to thickening of the coating of the electrode, and the thickening of the coating of the electrode will bring some A series of problems: ①The adhesion of the coating is reduced and it is easy to fall off; ②The coating of the electrode coating is not fully melted, because the substance contained in the coating is a mixture of inorganic non-metallic materials and metal materials, and its conductivity is poor, and the coating with a large thickness The conductivity is worse, which seriously affects the stability of arc combustion during welding, and at the same time weakens the effect of gas generation and slagging, and is also prone to defects such as insufficient metallurgical reaction in the molten pool, and the drug skin falls into the molten pool in pieces to form slag inclusions. , the quality of the weld is reduced; ③thick coating will cause the diameter of the electrode to increase, resulting in difficulties in vertical welding and overhead welding, and narrow gap welding cannot be performed. Larger grooves need to be opened during welding, resulting in an increase in the amount of electrodes used and a decrease in the amount of construction Increase; 3) When welding, the welding core melts first, and the coating melts later. Elements such as chromium and nickel in the coating are easily distributed unevenly after entering the molten pool, resulting in a decrease in the mechanical properties of the welded joint

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