Reduced Sintering Temperature Creates New Opportunities for PM Stainless Steel Exhaust Components

摘要

Currently PM exhaust flanges and HEGO bosses are manufactured from 409L or 434 L stainless steel powder by employing high temperature, hydrogen sintering. The high temperature sintering is necessary to achieve the large shrinkage needed to reach the specified sintered density set forth by OEM. Producers of exhaust components are today sintering between 1290 C to 1390 C to reach desired densities.410LV is a newly developed low chromium ferritic stainless steel which exhibits greater sintering activity at lower temperatures compared to the standard 409L. By selecting this alloy it is feasible to achieve a sintered density of 6.9 g/cc under mesh-belt sintering conditions (below 1180 C). This permits a significant reduction in the manufacturing cost and allows possible production of exhaust components without investment in high temperature capability. 410LV sintered at reduced temperature may offer adequate mechanical strength, corrosion resistance, and weldability for the exhaust flange and HEGO boss applications. This paper treats the properties of low temperature sintered 410LV, and compares those with the properties of low and high temperature sintered 409L.