As a casting part, the ductile iron cast gear cover housing requires comprehensive mechanical properties with high strength and good toughness, and quenching and tempering the cast iron parts. The process is as follows: the cast iron piece is heated to a temperature of 860-900 ° C to keep the matrix austenitized, and then quenched by cooling in oil or molten salt, and then tempered at a high temperature of 500-600 ° C to obtain tempered sorbite structure. The original spheroidal graphite has the same shape. After treatment, the strength and toughness are well matched, and it is suitable for the working condition of the ductile iron cast gear cover housing
At the same time, the ductile iron cast gear cover housing is often quenched and tempered at low temperature. The process is: the parts are heated to a temperature of 860-900 ° C, the original substrate is austenitized and then cooled in oil or molten salt to achieve quenching, and then heated and tempered at 250-350 ° C, the original matrix is converted back to The fire martensite and the retained austenite structure have the same shape of the original spheroidal graphite. The treated ductile iron cast gear cover housing has high hardness and certain toughness, retains the lubricating property of graphite, and improves the wear resistance.
ductile iron cast gear cover housings may have some defects due to various factors, which can be repaired in a corresponding way. For large defects, a composite application of a conventional weld repair process and a casting defect repair machine is recommended. For casting defects that are not required for quality and appearance, it can be repaired with a welding machine with a large amount of heat such as a argon arc welding machine and a high speed.