Abstract
Changes in residual stress and precipitation phenomena were studied, during aging for an austenitic stainless steel, SUS316L, cold-rolled with various degrees of reduction and surface ground by transmission electron microscopy and synchrotron radiation (SR) diffractmetry. After aging at 573 K, two kinds of precipitates were observed in the cold-rolled specimens. They were identified as M7C3 and M23C6 by SR diffraction and electron diffraction measurements. The precipitate M7C3 was formed both in grain interiors and at grain boundaries, while the precipitate M23C6 was formed in grain interiors. Precipitation was promoted with increasing cold-rolling reduction. Additionally, segregation of phosphorous was expected along grain boundaries. Residual stresses measured at a synchrotron radiation facility, SPring-8, showed that the compressive stress detected in cold-rolled specimens was changed into tensile stress with proceeding of aging. On the other hand, the tensile stress induced by surface grinding was decreased.
