Stainless Steel Casting: Metal Art from Liquid to Fine

2025-4-25

　　In the field of metal processing, stainless steel has become the preferred material for many industries due to its corrosion resistance, high strength, aesthetic durability, and other characteristics. And stainless steel casting, as a key process for transforming stainless steel from liquid to various complex shaped precision parts, is like a magic that gives metal life, occupying a pivotal position in modern industrial production. It is not only the integration of technology and art, but also an important force driving the development of various industries. ​

　　Stainless steel casting is a process that uses high temperature to melt stainless steel material into a liquid state, and then uses a specific mold to cast the liquid metal into shape. After cooling and solidifying, the desired shape of the parts is obtained. The core principle is based on the thermophysical properties of metals, that is, metals transform from solid to liquid at high temperatures, and the liquid metal fills the mold cavity under the action of gravity or external force, and then re solidifies into a solid state during the cooling process. ​

　　Stainless steel casting has significant characteristics. On the one hand, it can produce parts with complex shapes and fine structures, whether it is pump bodies with complex inner cavities, turbine blades, or decorative components with exquisite appearances, all of which can be achieved through casting processes. On the other hand, casting technology can achieve mass production by making multiple molds, which can quickly produce a large number of parts of the same specifications, meeting the scale requirements of industrial production. In addition, casting can adjust the composition and properties of stainless steel according to different usage requirements, such as improving corrosion resistance, enhancing strength, etc., to make the produced parts more suitable for practical application scenarios. ​

　　Mold is the key to stainless steel casting, and its quality directly affects the accuracy and surface quality of the castings. Mold design requires the use of computer-aided design (CAD) software for 3D modeling based on the shape, size, and usage requirements of the parts. During the design process, it is necessary to fully consider the shrinkage rate of the metal, the layout of the pouring system and riser, to ensure that the liquid metal can smoothly fill the mold cavity and obtain sufficient shrinkage during the solidification process. ​

　　Mold making usually uses technologies such as CNC machining and 3D printing. For complex molds, 3D printing technology can quickly form and greatly shorten the production cycle; CNC machining can ensure high precision of the mold, making the surface of the mold smooth and the dimensions precise. The completed mold still needs surface treatment and quality inspection to ensure that it meets the requirements of the casting process. ​

　　Stainless steel melting is the process of mixing various alloying elements in a certain proportion and melting them into a liquid state at high temperatures. Common melting equipment includes electric arc furnaces, induction furnaces, etc. During the smelting process, it is necessary to strictly control the temperature, time, and chemical composition. Different types of stainless steel, such as austenitic stainless steel, ferritic stainless steel, martensitic stainless steel, etc., have different alloy compositions and melting processes. ​

　　Taking austenitic stainless steel as an example, a certain amount of alloying elements such as nickel and chromium need to be added during melting to ensure its good corrosion resistance and comprehensive performance. At the same time, in order to remove impurities and gases and improve the purity of molten steel, external refining techniques such as argon oxygen decarburization (AOD) and vacuum blown oxygen decarburization (VOD) will also be used. ​

　　The process of injecting melted stainless steel liquid into the mold cavity through a ladle is called pouring molding. During the pouring process, pouring temperature, pouring speed, and pouring time are key parameters. Excessive pouring temperature can cause excessive shrinkage of the metal liquid, resulting in defects such as shrinkage and porosity; If the pouring temperature is too low, it will cause the flowability of the metal liquid to deteriorate, resulting in problems such as insufficient pouring and cold insulation. ​

　　The pouring speed and time also need to be adjusted according to the shape and size of the parts. For thin-walled parts, a faster pouring speed is required to ensure that the metal liquid can quickly fill the mold cavity; For thick walled parts, it is necessary to control the pouring speed appropriately to prevent defects such as slag inclusion and porosity. ​

　　After pouring, the casting gradually cools and solidifies in the mold. During the cooling process, the metal undergoes volume shrinkage. In order to reduce internal stress, prevent casting deformation and cracking, it is necessary to control the cooling rate. For some large or complex castings, slow cooling is usually used, such as natural cooling in sand molds; For small castings, rapid cooling methods such as water cooling or air cooling can be used. ​

　　After the casting cools to a certain temperature, demolding can be carried out. Be careful during the demolding process to avoid damaging the surface of the casting. For some castings with high precision requirements, cleaning is also necessary after demolding to remove surface impurities such as molding sand and burrs. ​

　　Subsequent processing is an important step in improving the quality and performance of castings, including heat treatment, surface treatment, and quality inspection. Heat treatment can improve the microstructure and properties of castings, such as eliminating internal stress through annealing, and increasing hardness and strength through quenching and tempering. ​

　　Surface treatment can make the surface of castings more beautiful and corrosion-resistant. Common surface treatment methods include sandblasting, polishing, electroplating, etc. Quality testing is a comprehensive inspection of the dimensional accuracy and internal quality of castings. Common testing methods include visual inspection, non-destructive testing (such as ultrasonic testing, radiographic testing), and destructive testing to ensure that castings meet design requirements and usage standards. ​