Draft decision
Hot-dip coating, also known as hot dipping, involves covering a metallic material by immersing it in a lower melting point liquid metal or alloy. The main characteristic of this method is the formation of an alloy layer between the base metal and the coating metal. Therefore, hot-dip coating is made of fused metal and metallized metal. Metallized metallic materials are typically steel, cast iron, and stainless steel. The low-melting-point metal used for hot dipping is zinc, aluminum, tin, and their alloys.
Investment casting relies on the final product as a copy of a paraffin-like material, pressed into a precise smooth mold, wax, coated with a multi-layered refractory material, for drying and curing the suspension to form a shell, and then solidifying in the shell. Then melt the molten metal into the shell, the liquid metal in the shell upon cooling after solidification to precision and smoothness after casting. This casting process can produce complex metal parts or exquisite handcrafted items that are intricate and close to the final product form, which can be used without machining or with minimal machining. Therefore, this is a process of obtaining a liquid metal surface. Compared to the sand casting method, it has the following characteristics:
The prospect of the state of heat treatment and thermochemical treatment technology
Foreign heat treatment manufacturers attach great importance to the cooling process of heat treatment. In accordance with the technical and technological requirements of the product, it can be slow, but oil quenching, single-gas quenching, and so on. Fast atmosphere recirculation is used to spray high-pressure gas into the cooling chamber, which regulates the flow rate and flow changes to achieve the cooling rate at a certain time to achieve the cooling curve required during heat treatment to ensure the quality of the heat treatment of parts. Before quenching the quenching gas with gas quenching, nitrogen, helium, etc., and now with strong air spraying, so that the workpiece is very quickly cooled, the surface quenching is only a very thin oxide film, gray, the color of the parts is still beautiful, saving a lot of nitrogen and inert gas to further reduce the cost of heat treatment.
Implementation of equipment for induction heat treatment
Induction heat treatment has the advantages of high heating speed, energy saving, non-oxidative decarburization, no environmental pollution, and high production efficiency. These advantages are widely recognized by heat treatment workers, so it has developed rapidly in the past ten years. Of course, this actual demand also significantly contributes to the development of domestic induction heat treatment equipment and technologies for improvement. For example, in "China FAW" Changchun, the company has more than 100 induction heat treatment units, of which almost 10 years - new or upgraded equipment - 50, almost all SCR equipment and IGBT audio equipment. Now, medium-sized FAW heat treatment parts can reach a weight of 291.3 kg, which accounts for 52% of all heat treatment parts. Induction heat treatment has truly strengthened half of the heat treatment.