Special welding electrode for surfacing and repairing broken teeth of cast iron gear

Abstract

The invention relates to a special welding electrode for surfacing and repairing broken teeth of a cast iron gear, belonging to the materials science and engineering field. The welding electrode comprises the following chemical components: 35-50wt% of marbles, 3-6wt% of chalk, 20-30wt% of fluorite, 1-3wt% of quartz, 2-4wt% of rutile, 4-7wt% of ferrotitanium, 2-5wt% of ferromolybdenum, 1-3wt% of high carbon ferromanganese, 1-3wt% of ferrosilicon, 4-7wt% of yttrium oxide and 10-14wt% of metallic nickel. The core wire is H08A steel welding wire. An adopted water glass binder has modulus of 2.7-3.0 and concentration (Baume degree) of 48-50. The surfacing welding electrode can be used for surfacing and repairing the broken teeth of the cast iron gear without preheating before welding and heat treatment after welding. The surfacing metal has higher crack resistance and has proper hardness (HB120-220) and abrasive resistance through alloying.

Description

technical field [0001] The invention relates to the field of material science and engineering, in particular to an electrode for overlay welding for repairing broken teeth of cast iron gears. Background technique [0002] Gears are one of the most widely used parts in mechanical transmission. For some unimportant gears with light load, low speed, no impact, precision and compact structure, they are often made of gray cast iron. Gray cast iron gears are generally subjected to stress relief annealing and normalizing after casting, and surface quenching after machining to improve wear resistance. Gray cast iron gears are mostly used in open gear transmission. In recent years, in closed transmission, the trend of using nodular cast iron instead of cast steel to make gears is increasing. However, cast iron gears have low toughness and are prone to failure under impact loads. [0003] There are many failure forms and influencing factors of gear transmission, among which gear to...

AI Technical Summary

Problems solved by technology

[0008] However, during the surfacing repair process of broken teeth of cast iron gears, problems such as tissue whitening and cracks are prone to occur; using traditional surfacing electrodes, even if the cast iron gears are preheated before welding (about 400 ° C), and after welding Under the condition of heat treatment, the cracking tendency of the surfacing metal and the heat-affected zone is still very large

At the same time, preheating before welding and heat treatment after welding will waste a lot of energy, complicate the welding process, increase the labor intensity of workers, and cause considerable economic losses to the enterprise