Common casting methods for Changzhou precision casting
The more commonly used in precision casting is investment casting, also known as lost wax casting: use appropriate investment material (such as paraffin) to make investment patterns; repeat the application of refractory coatings and refractory sand on the investment pattern, harden the shell and Dry; melt the internal investment mold to obtain the cavity; roast the mold shell to obtain sufficient strength and burn off the remaining investment material; cast the required metal materials; solidify and cool, and clear the sand after dehulling, Thus, a high-precision finished product is obtained. According to product needs or heat treatment and cold processing and surface treatment. For example, sand casting, mass-production factories should create conditions to adopt technologically advanced modeling and core making methods. The production line of the old-fashioned shock or pressure molding machine is not high in productivity, the labor intensity of workers is high, the noise is high, and it is not suitable for mass production. It should be gradually transformed. For small Precision casting, a horizontal or vertical partless box high pressure molding machine production line can be used. The solid shape production efficiency is high and the floor area is small. For middleware, various boxed high pressure molding machine production lines and gas can be used. Punching the molding line to meet the requirements of fast and high-precision molding production lines. The Stainless Steel casting core making method can be selected: cold core box, hot core box, shell core and other efficient core making methods.
Medium-sized large-scale castings can be considered using resin self-hardening sand modeling and core making.
For heavy-duty castings produced in small batches, manual modeling is still an important method. Manual modeling can be flexible to meet various complex requirements, and does not require many process equipment. Water glass sand molds, VRH method water glass sand molds, organic ester water glass self-hardening sand molds, clay dry molds, resin self-hardening sand molds, and cement sand molds can be used. For heavy-duty castings produced in a single piece, the pit modeling method has low cost and is put into production. fast. Multi-box modeling and split-box modeling are more suitable for mass-produced or long-term stereotyped products. Although molds, sand boxes, etc. start with high investment, they can be compensated by saving modeling man-hours and improving product quality.
Low-pressure casting, die casting, centrifugal casting and other casting methods are only suitable for mass production due to the expensive equipment and molds.
Conditional methods should fit
For example, the same is used to produce castings for large machine tool beds, and generally the core molding method is used, instead of making patterns and flasks, the core is formed in the pit; while other factories use the sand box molding method to make patterns. Different enterprises have different production conditions (including equipment, site, staff quality, etc.), production habits, and accumulated experience. They should consider what products are suitable and what products are not suitable (or not) based on these conditions.
Precision requirements and cost
The castings obtained by various casting methods have different accuracy, initial investment and productivity are not consistent, and the final economic benefits are also different. Therefore, to achieve more, faster, better, and save, we should take all aspects into consideration. A preliminary cost estimate should be made for the chosen casting method to determine a casting method with high economic benefits and which can guarantee the requirements of the casting.