Thread Content
The traditional steel used in household appliance manufacturing is mainly electro-galvanized steel sheet. In recent years, as the mechanical properties and surface quality of hot-dip galvanized steel sheets have continued to improve, their advantages over electro-galvanized steel sheets—such as lower production costs, better corrosion resistance, and less environmental impact—have become increasingly prominent. As a result, using them as a substitute for electro-galvanized steel sheets has become a major trend in the home appliance manufacturing industry both domestically and internationally. However, switching from electro-galvanized steel sheets to hot-dip galvanized steel sheets for home appliances is not a simple replacement process. Among these, how to select the right materials is well worth studying. The selection of hot-dip galvanized steel sheets for home appliances mainly involves aspects such as material grades, coating surface structure, and surface treatment methods. By selecting materials appropriately based on the usage conditions and quality requirements of specific home appliance components, it is possible to reduce material costs while ensuring the quality of the home appliance products, thereby enhancing their overall competitiveness. Based on the experience gained over the past few years in providing technical services to customers, the author believes that the following three aspects should be considered when selecting hot-dip galvanized steel sheets for home appliances: first, the choice of material grade; second, the selection of the surface structure of the coating; and third, the method of surface treatment for the steel sheet. Regarding the selection of material grades, steel used in home appliances is generally soft steel plate intended for stamping, and its mechanical properties can be classified according to **standards, European standards, Japanese standards, American standards, etc.; different standards correspond to different series of grades. Based on the degree of processing deformation that occurs during the use of the material, steel used in home appliances is generally classified into categories such as general purpose, stamping purpose, deep drawing purpose, and ultra (special) deep drawing purpose, according to its suitability for stamping. Overall, stamping household appliance sheet metal parts is not particularly difficult, but there are significant differences among different parts; therefore, materials should be selected appropriately based on the way the parts deform, their deformation characteristics, and the quality requirements. The main problems that may occur in the stamping of home appliance sheet metal parts are cracking, warping, and springback. Since stamping defects in steel plates are also related to the condition of the dies and the stamping process, a proper selection of materials should take into account the user’s own die factors and process factors as well. Based on the stamping results of the parts and the technical quality requirements of different products, the following factors should be given priority consideration when selecting the material grade: the parts must not develop cracks or significant necking after stamping. Material cracking and necking will directly affect the strength, safety, and corrosion resistance of parts; these are types of product defects that must be avoided. To ensure that such phenomena do not occur during the stamping process of parts, it is necessary to conduct deformation and stress analysis on the main deformation areas of the specific parts, and select appropriate materials based on the forming properties of those materials. Changes in surface quality resulting from the mechanical properties of the material. Surface quality is very important for home appliance sheet metal parts, especially those with an external appearance. The exterior components of home appliance products should not only meet the requirements regarding the structural strength of the product, but also possess resistance to indentation, and sliding lines during stamping should be avoided. Wrinkling of the material after stamping and springback of the parts. Wrinkling is related to product design and the mechanical properties of materials. Localized, minor wrinkling is generally negligible in interior components, but it is not allowed to appear on exterior components. Springback often occurs in parts with relatively simple deformation patterns, primarily bending deformation, and in such cases it is necessary to take into account both the material cost and the required level of springback.