As a commonly used high-performance material, 316L stainless steel is widely used in engineering fields. This paper aims to explore the coarse powder injection molding process of 316L stainless steel, and improve the quality and performance of molded parts by optimizing parameters and process conditions. The experimental results show that the coarse powder injection molding process can effectively realize the manufacture of parts with complex shapes, and has high molding efficiency and economy. In addition, by changing different process parameters such as injection pressure, injection speed, and sintering temperature, the fluidity and densification degree of 316L stainless steel coarse powder can be adjusted, so as to obtain molded parts with good mechanical properties and densification. In summary, the 316L stainless steel coarse powder injection molding process has broad application prospects, which provides a reference for further improvement of the process.
Key words: 316L stainless steel, coarse powder injection molding, process parameters, mechanical properties, density

Introduce
Stainless steel materials are widely used in many fields due to their good corrosion resistance, high temperature performance and mechanical strength. 316L stainless steel is a common low-carbon stainless steel with excellent corrosion resistance and weldability, and is widely used in the manufacture of chemical equipment, medical equipment and aerospace fields. The coarse powder injection molding process in powder metallurgy technology can effectively manufacture parts with complex shapes, with less material waste and high forming efficiency, so it has become one of the research hotspots.
experimental method
2.1 Material preparation
In this study, 316L stainless steel coarse powder treated by powder metallurgy was used as raw material. The particle size distribution of the coarse powder is between 50 and 200 microns.
2.2 Optimization of injection molding process parameters
Through the adjustment and optimization of injection molding process parameters, the effective molding of 316L stainless steel coarse powder was realized. The main parameters considered include injection pressure, injection speed and sintering temperature. During the experiment, through a series of experiments and analysis, the optimal combination of process parameters was determined.
Results and discussion
3.1 Forming quality and performance
Through the optimized injection molding process, 316L stainless steel parts with complex shapes were successfully manufactured. Scanning electron microscope (SEM) observation showed that the surface finish of the molded parts was good without obvious defects. X-ray diffraction (XRD) analysis showed that the crystal structure of the molded parts was similar to that of the 316L stainless steel material obtained by the conventional process. The results of mechanical property tests show that the molded parts have high tensile strength and elongation, which meet the requirements of engineering applications.

3.2 Process parameter optimization
By changing the process parameters such as injection pressure, injection speed and sintering temperature, the fluidity and densification degree of 316L stainless steel coarse powder were regulated. The experimental results show that properly increasing the injection pressure and injection speed can improve the compactness and mechanical properties of 316L stainless steel coarse powder. However, too high a sintering temperature may lead to grain growth and deformation of the molded part.
In summary
In this study, the potential of the process for manufacturing complex shaped parts was verified by studying the coarse powder injection molding process of 316L stainless steel. Optimized process parameters enable high-quality molded parts with good mechanical properties and compactness. This process provides a new way for stainless steel powder injection molding, and also provides a reference for further improving the process and expanding the application field.