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

Abstract

Disclosed is a special welding electrode for surfacing and repairing broken teeth of a light-load and low-speed gear. Chemical components of the coating of the special welding electrode in weight percent (wt %) include 50-55% of marble, 4-6% of chalk, 25-30% of fluorite, 1-3% of quartz, 1-3% of medium carbon ferrochromium, 1-3% of ferrotitanium, 1-3% of high carbon ferromanganese, 1-3% of ferrosilicon, 1-3% of lanthanum trioxide and 1-3% of metallic nickel, and a core wire is an H08A steel welding wire. The welding electrode is capable of surfacing and repairing the light-load and low-speed forged steel gear without preweld preheating or post-weld heat treatment, deposited metal has high cracking resistance, and the welding electrode is extremely convenient to use on site. The surface hardness of the repaired light-load and low-speed gear ranges from HBS (Brinell hardness scale) 200 to HBS 280, and the service life of the repaired gear is three times that of an original gear.

Description

technical field [0001] The invention relates to a welding rod, in particular to a welding rod for overlay welding. 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; according to the gear speed, it is generally divided into low-speed gear (1~9 m / s), medium-speed gea...

AI Technical Summary

Problems solved by technology

Broken teeth are the main form of damage to light-load and low-speed forged steel gears, especially broken teeth are generally emergencies. In the absence of spare gears, broken teeth will seriously affect normal production and bring huge economic benefits to enterprises. loss

[0004] In recent years, many companies at home and abroad have tried to repair light-load, low-speed forged steel gears with broken teeth by surfacing welding. However, since light-load, low-speed forged steel gears are made of low-carbon steel or medium-carbon steel, their carbon Higher, especially under the conditions of no pre-weld preheating and post-weld heat treatment on site, cracks are prone to appear on the gear surface, which will reduce the quality of the gear after welding and even fail to repair, thus limiting the broken teeth of light-load and low-speed forged steel gears Wide application of overlay welding repair technology