Sintered flux for two phase stainless steel

Abstract

The invention discloses a sintered flux for two phase stainless steel. The sintered flux comprises the dry powder components by weight percent: 24-32% of MgO, 12-23% of CaF2, 12-18% of ZrO2, 10-15% of Al2O3, 9-14% of SiO2, 2-10% of CaO, 1-3% of rare earth fluoride, 0.5-2% of sodium fluosilicate, 0.5-2% of chromium oxide green, 0.5-2% of deoxidier, 2-8% of alloying agent, and the balance chromium metal, wherein the deoxidier is Si-Fe in which the content of Si is not less than 70%, and the alloying agent contains 1.5-2.5% of ferromolybdenum in which the content of molybdenum is not less than 50%. The sintered flux disclosed by the invention is matched with ER2209 solder wires, is suitable for the welding and overlaying of two phase stainless steel containing 22% of Cr; the welding is ruled and stable, the slag detachability is excellent, and the weld pass is even in width, moderate in pile height, smooth in transition; the defects of gas pits, intermediate crystallization lines, slag bonding and the like are overcome; and the flux has high content of deposited metal ferrite, excellent mechanical property and corrosion resisting property.

Description

[0001] technical field [0002] The invention relates to a welding material technology, in particular to a sintered flux for duplex stainless steel. Background technique [0003] Duplex stainless steel is a kind of stainless steel composed of austenite and ferrite in a certain proportion. Among them, the ferrite phase and the austenite phase account for about half. Even if the amount of a certain phase is small, the general amount is small Also need to reach 30%. Duplex stainless steel combines the characteristics of austenitic stainless steel and ferritic stainless steel. Compared with ferritic stainless steel, duplex stainless steel has high toughness, low brittle transition temperature, significantly improved intergranular corrosion resistance and welding performance; at the same time, it retains some characteristics of ferritic stainless steel, such as 475 ℃ brittleness, thermal High conductivity, small coefficient of linear expansion, superplasticity and magnetism. ...

AI Technical Summary

Problems solved by technology

Since the Cr content of duplex stainless steel is significantly higher than that of ordinary austenitic stainless steel, and the Ni content is significantly lower, and Cr is easy to burn out, so a part of it needs to be transferred from the flux, so the basicity of the ordinary austenitic stainless steel sintering flux provided by the above invention patent , Oxidation, melting point of slag crust, slag viscosity, surface tension, interfacial tension and other parameters are difficult to match with duplex stainless steel welding wire, and gas pressure pits, intermediate crystallization lines, lateral sticky slag, edge Welding defects such as sticky slag

And so far, no patent report on duplex stainless steel submerged arc welding flux has been seen