Mechanical Properties of High Temperature Sintered P/M 409LE and 409LNi Stainless Steels Utilized in the Manufacturing of Exhaust Flanges and Oxygen Sensor Bosses

Powder metal (P/M) 400 series stainless steel exhaust components (flanges and oxygen sensor bosses) are being increasingly used in US made automobiles. These components are shown to have superior leak-tightness and resistance to corrosion and oxidation, when compared to wrought stainless steel exhaust components.

This paper compares the yield, tensile, impact, and fatigue strengths of two popular exhaust component materials, namely 409LE and 409LNi (a nickel-modified version of 409L), in the as-sintered condition. Data presented are based on samples sintered in 100% hydrogen using a commercial sintering practice, exhibiting sintered densities in the range of 7.2 to 7.3 g/cm³. Fatigue strengths were determined using the rotating beam test method, per MPIF Standard 56.