Flux-cored wire and method for welding cold-rolled back-up roll by same

Abstract

The invention discloses a flux-cored wire and a method for welding a cold-rolled back-up roll by the same, and relates to the welding technology. By using a steel strip as a sheath, the flux-cored wire comprises the following components in percentage by mass: 0.15 to 0.50 percent of carbon, 0.10 to 1.00 percent of silicon, 0.30 to 2.00 percent of manganese, 3.50 to 7.00 percent of chromium, 0.50 to 2.50 percent of molybdenum, 1.00 to 3.50 percent of tungsten, 0.20 to 1.00 percent of vanadium, 0.20 to 3.00 percent of nickel, 0 to 0.03 percent of sulfur, 0 to 0.03 percent of phosphorus, and the balance of iron. The flux-cored wire needs to maintain the surfacing interpass temperature of the cold-rolled back-up roll between 300 and 350 DEG C during constant temperature surfacing work. The flux-cored wire well solves the problem that the intensity of a surfacing material is not matched with the toughness after surfacing of the cold-rolled work roll, so that the hot-rolled back-up roll has high intensity and excellent toughness. Therefore, the service life of the cold-rolled back-up roll is improved.

Description

technical field

[0001] The invention relates to the field of welding technology, in particular to a flux-cored welding wire and a method for welding cold-rolled backup rolls thereof. Background technique

[0002] Cold-rolled back-up rolls are an important bulk consumption part in cold-rolled sheet production, and their quality accuracy directly affects the quality of rolled coils, while the roll consumption of cold-rolled rolls is an important technical and economic index. Due to its harsh working conditions and extremely high working stress, the surface often fails in the form of peeling, falling off, and abrasion during the working process. Therefore, the surface is required to have relatively high hardness, wear resistance and crack resistance. At present, most of the cold-rolled backup rolls at home and abroad use carbon and alloy element content such as: 9Cr2, 9Cr2Mo, 9CrV, 75CrMoV, 86CrMoV 7 , 85CrMoV7 and other materials are integrally manufactured, and then surface ...