Powder metallurgy stainless steel can be made into parts. The stainless steel water smelted in the induction furnace flows out from the leak hole of the nozzle, atomized with high-pressure water, and condensed to obtain stainless steel powder. The powder is treated by dehydration, drying, classification, annealing and other processes, and the bulk density of the water-atomized stainless steel powder is 2.5~3.2g/cm. Press and form under the pressure of 550~830MPa. The compacts are sintered in a hydrogen or decomposed ammonia atmosphere with a dew point of -45~-50°C. Vacuum sintering can also be used, and the sintering temperature is 1120~1150℃. When better mechanical properties and corrosion resistance are required, sintering temperatures as high as 1315C are used.
Powder metallurgy stainless steel can be made into steel. The stainless steel water is atomized into powder with high pressure nitrogen, the powder particles are spherical, the bulk density is about 4.8g/cm, and the oxygen content of the powder is less than 100×10. Spherical stainless steel powder can also be produced by rotating electrode milling method, and the oxygen content is (40~70)×10. These stainless steel powders were put into a package, vacuum-sealed, cold isostatic pressing at 5 kPa, and then hot isostatic pressing at 1050° C. and 2 kPa for densification. Cold isostatic pressing can also be hot-extruded into dense rods and tubes at a temperature of 1200°C. Compared with ordinary cast and forged stainless steel, the segregation of nickel, chromium and molybdenum elements of powder metallurgy stainless steel is small, the grain size is much finer, and the sulfide inclusions are small and evenly distributed. so improved
Stainless Steel Powder Metallurgy Parts
Stainless Steel Powder Metallurgy Parts
Mechanical properties and corrosion resistance.
The main grades of powder metallurgy stainless steel are 1Crl3, 2crl3, 1Crl7Mo, 00Cr18Nil0, 00Cr17Nil4M02, OCrl7N14Cu4Nb, etc. In the harsh environment of offshore operation, in order to improve corrosion resistance and strength, special stainless steel with high molybdenum, high nickel, nitrogen and manganese is used. However, the hot workability of this steel is poor, and hot cracks are easily formed during welding. In order to overcome these shortcomings, powder metallurgy hot isostatic pressing or hot extrusion process is used to directly produce isotropic, segregation-free powder metallurgy stainless steel flanges, steel pipes and other parts.