Heat treatment process of carbon structural steel

Abstract

The invention discloses a heat treatment process of carbon structural steel, which comprises the following steps of: quenching; self-checking; cleaning; tempering; and testing, wherein the step of quenching is carried out in a sealed box-type multi-purpose furnace, the quenching temperature is controlled at 840-900 DEG C, the temperature preservation time is 60-120min, oil is adopted as a quenching medium for cooling, the temperature of the cooled oil is controlled at 60-100 DEG C, and the cooling time is controlled for 20-30min. According to the invention, as the quenching process of the traditional medium-carbon structural steel is improved, the sealed box-type multi-purpose furnace is applied to the step of quenching of the medium-carbon structural steel, so that the quality requirements of a product are ensured, and simultaneously, the production efficiency is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of heat treatment of steel workpieces, and in particular relates to a heat treatment process of carbon structural steel. Background technique [0002] Medium carbon structural steel has good mechanical properties, low price and wide sources, so it is widely used in various important structural parts in machinery manufacturing, especially those connecting rods, bolts, gears and shafts that work under alternating loads etc.; but its biggest weakness is low hardenability, so it is necessary to use a quenching medium with a large cooling rate when quenching. Water is the earliest, most widely used, and most economical quenching medium. It is cheap and easy to obtain, non-toxic, non-combustible, stable in physical and chemical properties, and strong in cooling capacity. Therefore, water or water-soluble steel is generally used in industrial applications for medium carbon structural steel Quenching medium. At pr...

AI Technical Summary

Problems solved by technology

At present, most companies use water-based quenching after heating in a box-type furnace, but the box-type furnace needs manual operation, resulting in a decline in the product qualification rate; the box-type furnace consumes a lot of energy and high production costs; cost automated production

With the rapid development of the industrial economy, many manufacturers have equipped sealed box-type multi-purpose furnace equipment; however, due to the large amount of water vapor generated after the water is heated, the water vapor will generate high pressure in the sealed box-type multi-purpose furnace, causing the equipment to explode. Therefore, the use of water-based medium heat treatment in sealed box furnaces is absolutely prohibited, which limits the automatic heat treatment of medium carbon structural steel in sealed box-type multi-purpose furnaces. For a long time, sealed box-type multi-purpose furnaces have been used for chemical heat treatment, not carbon Quenching and tempering treatment of plain structural steel