Importance of quality control in large stainless steel casting and introduction to casting technology

Importance of quality inspection of large stainless steel casting: 

precision casting industry is developing faster and faster nowadays, which also leads to uneven quality of each product. If we produce a product and directly sell it to others regardless of its quality, the quality of the product cannot be guaranteed, and the user is not assured when using it. These principles are also applicable to large-scale stainless steel casting. Do not find out the reason after large-scale stainless steel casting is unqualified, or continuously improve the product quality improvement as the overall application ability in the production and processing process. Of course, there is a premise that based on the actual application ability, the advantage of the actual performance development of the product shall be continuously enhanced, and the use effect of the product in all aspects shall be taken as the target. To make the quality of the large stainless steel casting higher than that of the previous floor, there shall be a perfect inspection standard, which can reflect the overall performance superiority of the product and make it more competitive. How should we do it? In order to strengthen the quality inspection of large stainless steel casting, the Company can strengthen the product quality inspection in the actual implementation process; Specify detailed rules for product quality inspection; Strengthen the standardization of large stainless steel casting process, etc. 

Casting process of large stainless steel casting: 

1. Due to poor mobility of molten steel, in order to prevent cold insulation and insufficient pouring of steel castings, the wall thickness of steel castings shall not be less than 8mm; The structure of the pouring system shall be as simple as possible, and the section size shall be larger than that of the cast iron; Dry cast or hot cast; Appropriately increase the pouring temperature, generally 1520 ° - 1600 ° C, because the pouring temperature is high, the superheat of molten steel is large, the time to keep liquid is long, and the mobility can be improved. However, too high pouring temperature will cause such defects as coarse grain, thermal crack, air hole and sand adhesion. Therefore, the pouring temperature of small, thin-walled and complex castings is about+150 ℃ as the melting point temperature of steel; The pouring temperature of large and thick-wall castings is about 100 ℃ higher than the melting point. 2、 Since the shrinkage of cast steel greatly exceeds that of cast iron, in order to prevent shrinkage cavity and shrinkage defects of castings, risers, cold irons and subsidies are generally adopted in the casting process to achieve sequential solidification. 3、 In order to prevent shrinkage cavity, shrinkage porosity, air hole and crack defects of steel castings, the wall thickness shall be uniform, sharp corner and right-angle structure shall be avoided, sawdust shall be added to the molding sand for casting, coke shall be added to the core, and hollow core and oil sand core shall be used to improve the collapsibility and air permeability of sand or core. 4、 The melting point of cast steel is high, and the corresponding pouring temperature is also high. Under high temperature, the molten steel interacts with the cast material, which is very easy to produce sand adhesion defects. Therefore, the artificial quartz sand with high fire resistance shall be used as the cast mold, and the coating made of quartz powder or zirconium sand powder shall be brushed on the surface of the cast mold. In order to reduce the source of gas, improve the mobility of molten steel and the strength of the cast mold, most steel castings shall be cast in dry or fast dry mode, If CO2 hardened water glass sand type is used. Stainless steel precision casting is a very important process in metallurgical production. Except for a few products directly molded by powder metallurgy and other methods, almost all metal products and components cannot be produced without casting. They are either solidified into ingots after smelting, and then made by various hot and cold processing, or made by direct casting. 

Development of large-scale stainless steel casting: With the development of relevant large-scale stainless steel casting industry, enterprises should timely adjust the production scale and product structure, keep pace with the times, and better grasp the future development trend to adapt to the market demand in the new period, so as to achieve better development in the future. In recent years, the production of large stainless steel casting in China has been rising year by year, and the development is very fast. What is the reason? It is understood that there are mainly the following reasons: 1. Driven by the trend of automobile lightweight, the global large stainless steel casting market has a huge demand, and in recent years, with the internal optimization and upgrading of the automobile industry, aluminum castings are gradually used to replace gray iron castings, thereby continuously stimulating the rising demand for aluminum alloy Die Castings. 2. Due to the development of the global die casting industry, the demand for aluminum alloy die castings in various industries is also increasing. At the same time, driven by the trend of global economic integration, the global die casting production focus is gradually transferred to China. In addition, China's unique advantages in labor force and aluminum resources, which will undoubtedly lead to the rapid development of the die casting industry. 

In recent years, with the improvement of China's casting technology and quality of castings, China's casting industry has been increasingly recognized and approved by foreign enterprises, and new casting orders are coming. The output of large stainless steel casting in China is rising year by year, and the overseas trade of the casting industry is also developing vigorously.