Special welding electrode for surfacing and repairing broken teeth of medium-load and medium-speed gear

Abstract

Disclosed is a special welding electrode for surfacing and repairing broken teeth of a medium-load and medium-speed gear. Chemical components of the coating of the special welding electrode in weight percent (wt %) include 25-35% of marble, 14-20% of fluorite, 3-5% of quartz, 2-4% of chalk, 4-6% of high carbon ferrochromium, 2-4% of high carbon ferromanganese, 3-5% of graphite, 2-4% of ferrosilicon, 2-4% of ferrotitanium, 3-5% of ferromolybdenum, 4-6% of lanthanum trioxide, 7-9% of metallic nickel, 6-8% of medium carbon ferrochromium and 3-5% of ferrovanadium, and a core wire is an H08A steel welding wire. When the special welding electrode is used, preheating at the temperature of 200-300 DEG C is performed before welding, and tempering at the temperature of 100-200 DEG C is performed after welding. The special welding electrode is convenient to use on site, easy in welding and non-cracking after welding. The surface hardness of the gear after welding ranges from HRC (Rockwell hardness) 50 to HRC 55, and the service life of the repaired gear is three to four times that of an original gear.

Description

technical field [0001] The invention relates to a surfacing welding technology, in particular to a surfacing welding technology for repairing broken teeth of medium-load and medium-speed forged steel gears. Background technique [0002] Gear is one of the most widely used parts in mechanical transmission. It not only plays an important role in products such as automobiles, tractors, machine tools, and hoisting machinery, but also uses a large amount. According to the type of material, gears mainly include forged steel, cast steel, cast iron and non-ferrous metals. Among them, forged steel is the most widely used, and gears for important purposes are usually made of forged steel. The selection of specific gear materials is mainly determined according to the size of the load, the speed of the gear and the precision requirements of the gear when the gear is working. According to the load of the gear, it is generally divided into light load, medium load and high load; accordin...

AI Technical Summary

Problems solved by technology

[0005] In recent years, many enterprises at home and abroad have tried to repair medium-load and medium-speed forged steel gears with broken teeth by surfacing welding, but because medium-load and medium-speed forged steel gears are made of medium carbon steel or alloy quenched and tempered steel Made of low-hardenability steel with high carbon equivalent, even under the conditions of pre-weld preheating and post-weld heat treatment, cracks will appear on the gear surface, which will reduce the quality of the gear after welding and even fail to repair, thus limiting the Wide application of surfacing welding repair technology for rapid forging steel gear broken teeth