Gas protective welding flux cored wire for welding heat resistant steel

Abstract

The invention belongs to a gas protective welding flux cored wire for welding heat resistant steel. The gas protective welding flux cored wire comprises low-carbon steel metal skin and a flux core, wherein the low-carbon steel metal skin comprises the following components in percentage by weight: 0.01 to 0.1 percent of C, 0.1 to 0.4 percent of Mn, 0.01 to 0.03 percent of Si, 0.005 to 0.015 percent of S, 0.005 to 0.015 percent of P and the balance of iron; the flux core accounts for 14 to 25 percent of the total weight of the welding wire and comprises the following components in percentage by weight: 1.2 to 3.0 percent of medium-carbon ferromanganese, 0.20 to 2.0 percent of ferrosilicon powder, 0.05 to 0.5 percent of magnesium powder, 1.5 to 2.0 percent of metal chromium powder, 0.2 to 2.0 percent of ferromolybdenum powder, 0.05 to 0.2 percent of electrically fused magnesia, 0.01 to 0.3 percent of fluoride and 7 to 15 percent of iron powder; and the components are mixed uniformly, the mixture is coiled on a thin steel strip made of low-carbon steel to form strips, and the strips are drawn to form wires. The gas protective welding flux cored wire has the characteristics of no molten slag on deposited metal after welding, capability of performing continuous multi-layer welding without slag removal, high welding process property, stable electric arcs, small splatter, attractive appearance of weld joints and the like, the welding efficiency is improved by 20 to 40 percent, and vertical downward welding can be realized by short circuiting transfer.

Description

technical field [0001] The invention belongs to welding wire for metal material welding production, in particular to a gas-shielded welding flux-cored welding wire for heat-resistant steel welding; the flux-cored welding wire is especially suitable for heat-resistant steel for 15CrMoR low-alloy containers whose working temperature is lower than 520°C Welding and multi-layer continuous welding without slag cleaning. Background technique [0002] 15CrMoR steel is a pearlitic heat-resistant steel widely used all over the world. Its chemical composition (weight percentage) is: C: 0.12-0.18%, Cr: 0.80-1.20%, Mo: 0.45-0.60%, Mn: 0.40-0.70% , Si: 0.15-0.40%, S≤0.010%, P≤0.025%, the balance is iron and unavoidable impurities; its mechanical properties are tensile strength Rm: 450-590MPa, yield strength ReL≥275MPa, elongation A≥19%, 20℃kv≥31J, it is the main steel grade used in the manufacture of superheaters, headers and main steam pipes of high-pressure, ultra-high pressure and su...

AI Technical Summary

Problems solved by technology

Therefore, this kind of patented technology still has defects such as inability to realize continuous multi-layer welding, low welding efficiency, and high labor intensity of operators.

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