Innovative Practices and Applications of 304 Stainless Steel Powder Metallurgy

304 stainless steel is highly sought after in precision manufacturing due to its excellent corrosion resistance and mechanical properties. Powder metallurgy technology achieves dual breakthroughs in material utilization and part precision through a net-shaping process of "powder → forming → sintering." As a company deeply rooted in this field, Jiangsu Mimo Metal is driving the technological advancement and iterative upgrading of 304 stainless steel powder metallurgy processes.

The core of 304 stainless steel powder metallurgy begins with raw material preparation. High-quality powder serves as the foundation of the process, typically produced by water atomization—where molten stainless steel is shattered and condensed by high-pressure water jets, forming irregular particle powder. This powder is then subjected to dehydration, classification, and annealing, with the bulk density controlled within the range of 2.5–3.2 g/cm³. Jiangsu Mimo Metal strictly selects 304 powder with particle sizes between 4–25 microns at this stage, laying the groundwork for subsequent precision molding. Some advanced processes further reduce powder oxygen content and enhance material stability through secondary deoxidation and nitrogen-protected atomization.

Shaping and debinding are critical steps in determining part accuracy. Jiangsu Mimo Metal employs Metal Injection Molding (MIM) technology, mixing 304 stainless steel powder with a binder in a 60:40 volume ratio to create feedstock. Under high pressure, the material is injected into precision molds to form "green parts." This process overcomes the limitations of traditional pressing, enabling the one-piece molding of complex and irregular structures with dimensional tolerances controlled within ±0.3 millimeters. After forming the green parts, debinding treatment is required to remove the binder, clearing the way for sintering densification.

High-temperature sintering and post-processing ultimately impart the desired properties to the parts. Sintering must be conducted in an ammonia decomposition or hydrogen protective atmosphere, typically at temperatures of 1120–1150°C. For higher performance requirements, the temperature must be raised to 1315°C. Jiangsu Mimo Metal achieves full bonding of powder particles through precise temperature-controlled sintering, followed by solid solution hardening treatment—where the sintered part is heated to 1100°C and then rapidly cooled to prevent the precipitation of chromium nitrides, significantly enhancing corrosion resistance. Through this process, the finished product achieves a density of over 7.3g/cm³, with mechanical properties and corrosion resistance approaching those of melt-forged steel.

Today, Jiangsu Mimo Metal's 304 stainless steel powder metallurgy products are widely used in industries such as automotive, electronics, and power tools. Combining the advantages of complex structures, precise dimensions, and high performance, these products highlight the industrial value of powder metallurgy technology. With continuous process optimization, 304 stainless steel powder metallurgy will unlock greater potential in high-end manufacturing sectors.