Thin-shell sand culturing casting simple technology

Abstract

The invention relates to a precision steel casting industry, and provides a thin-shell sand culturing casting simple technology for precision steel casting. A sodium silicate binder is adopted in shell manufacturing, quartz powder and the small amount of quartz fine sand are used in surface layer powder, a lubricating agent and an antifoaming agent are added to prepare a coating, quartz sand, two layers and a transition layer are scattered, and a coating is prepared through the sodium silicate binder, the quartz powder and mullite powder; mullite sand and a crystallization aluminium chloride solution are scattered to be hardened to prepare a thin shell; a reinforcing layer is not needed, roasting after dewaxing can shorten the heat preservation time, and burning through is easy; defects of shell layering, cracks, air holes, sand clamping, insufficient hardening and the like are overcome. Culturing sand in a dedicated sand box is put, after the sand is jolted through a vibration table, the sand is casted, and an abrasive disc upper cover box is lifted after 15 minutes to 30 minutes, and the culturing sand can fall in a sand collection hopper; sequential solidification cooling is accelerated, and the function of reinforcing the shell in a multilayer manner is achieved; the production period is short, the technology is simple, and the cost is low; compared with an original reinforcing layer shell casting, the cost of a casting of each tonnage is reduced by about 200 yuan; and the technology is suitable for manufacturing pump valve type fine castings of large specifications.

Description

technical field [0001] The invention relates to the precision cast steel industry, and adopts a simple process of thin-shell sand casting for precision pump and valve castings. The application of this technological process can meet the casting requirements of precision steel castings for pumps and valves. It not only ensures the quality of precision steel castings, but also simplifies the shell-making process, shortens the production cycle, and reduces production costs. Background technique [0002] Precision steel castings for pumps and valves are expensive and have the functions of high temperature, high pressure, wear resistance and corrosion resistance. Due to the complex shape, most of them are castings, and these castings have high requirements for geometric dimensions, shape and position tolerances, and surface accuracy. These castings are usually made of water glass quartz sand. Small pieces below 25 kg need to be repeatedly coated with two layers, a transition laye...