PM stainless steel's resistance to scaling

In North America, conversion of automotive exhaust systems from carbon steel to stainless steel has been progressing steadily since the mid-1990s. In an all stainless steel exhaust system, PM stainless steel exhaust flanges and HEGO (hot exhaust gas oxygen sensor) bosses are frequently selected over wrought (stamped and formed) stainless steel components. This is because PM stainless steel provides significant advantages in performance, cost and design flexibility, over their wrought counterparts. The improved performance is primarily due to the fact that PM stainless steel is more resistant to spalling of oxide scales in application-specific cyclic oxidation tests, compared with wrought stainless steel…