Stainless Steel Porous Filter Element Vacuum Sintering

Metal filter materials have the advantages of high temperature resistance, high filtration accuracy, not easy to deform, high mechanical strength, long service life, and reproducibility. Stainless steel filter materials are widely used because stainless steel has corrosion resistance, oxidation resistance and excellent weldability, and is used well in high temperature environments of 500 to 600 °C. However, the stainless steel filter element will be broken and broken during the use process. The main reason is that the sintering atmosphere, sintering temperature and holding time have a great influence on its performance during the preparation process of the stainless steel filter element, resulting in a decrease in strength. This article describes one of these sintering processes.

The domestic 316L stainless steel powder is used, and its particle size ranges from 100 to 160 mesh. Its chemical composition conforms to GB/T20878-2007. The preparation process of the filter element test sample is as follows:

Powder Preparation – Molding – Cold Isostatic Pressing – Sintering – Pipe Handling – Sample Processing – Sample Testing

The stainless steel samples were prepared by CIP, the experimental pressure was 100-180 MPa, the tube blank size was 50 mm × 500 mm × (3-4) mm, and then placed in a vacuum atmosphere for sintering, the sintering temperature was 1250 °C, the holding time was 2 h, and the furnace was cooled. to room temperature.

After vacuum sintering, the appearance of the sample is gray-white, the surface is clean and bright, and the sintering neck is fully developed. The pores of vacuum sintering are smooth and round, the particle surface is smooth, the gas permeation resistance is small, and the gas permeability is high. The ring tensile strength of vacuum sintered stainless steel filter element samples is 158MPa to 165MPa, and the ring tensile strength is higher. The 316L stainless steel porous material sintered in this way can obtain the best permeability coefficient, larger maximum pore size and maximum ring tensile strength.

The RVS series vacuum sintering furnace produced by SIMUWU is a high-quality product to complete this kind of process. It has the characteristics of good temperature uniformity and high temperature control accuracy.