Gas protective flux cored wire for welding vanadium-containing heat resistant steel

Abstract

The invention belongs to a metal powder type gas protective flux cored wire for welding vanadium-containing heat resistant steel. The metal powder type gas protective flux cored wire comprises low-carbon steel skin and a flux core, wherein the low-carbon steel 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, 0.1 to 1 percent of ferrovanadium, 0.05 to 0.2 percent of electrically fused magnesia, 0.01 to 0.2 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 to form strips, and the strips are drawn to form wires. The metal powder type gas protective 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 speed, high efficiency and welding process property, stable electric arcs, small splatter, attractive appearance and the like, 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 metal powder type gas shielded welding flux-cored welding wire for welding heat-resistant steel containing vanadium; the flux-cored welding wire is especially suitable for welding heat-resistant steel for 12Cr1MoVR type low-alloy containers And multi-layer continuous welding without cleaning slag. Background technique [0002] 12Cr1MoVR steel is a pearlitic heat-resistant steel widely used all over the world. Its chemical composition: C: 0.08-0.15%, Mn: 0.40-0.70%, Si: 0.15-0.40%, Cr: 0.90-1.20%, Mo: 0.25- 0.35%, V: 0.15-0.30%, S≤0.010%, P≤0.025%, the balance is iron and unavoidable impurities; mechanical properties: tensile strength Rm: 440-590Mpa, yield strength ReL≥245Mpa, elongation Rate A≥19%, 20℃kv≥34J, it is the main steel grade used for superheater, header and main steam pipeline of high pressure, ultra high pressure and subcritical power station bo...

AI Technical Summary

Problems solved by technology

When using electrode (E5515-B2-V) welding, the welding process performance and mechanical properties are good, but using electrode arc welding, semi-automatic or automatic welding is not possible, and each electrode must lose 20-30mm of electrode head, which will cause waste of materials And the welding efficiency is low; in order to improve the welding efficiency, solid or common flux-cored wire is usually used for welding. Compared with the solid wire, the deposition speed of the flux-cored wire is 20 times higher than that of the solid wire under the same welding specification. -30%; but at present, ordinary flux-cored wire is used to weld vanadium-containing heat-resistant steel for 12Cr1MoVR low-alloy containers, so the welding process performance and physical and chemical properties are poor, and a large amount of slag will be generated during the welding process, which cannot be carried out. Multi-layer continuous welding without slag removal not only reduces the welding efficiency, but also increases the labor intensity and welding cost of the welder, and the comprehensive performance of the weld is poor and other defects

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