Strength of a weld-seam metal and glass-enamel coating composite under conditions of cyclical creep

Abstract

In the temperature interval 293–573 K we have experimentally established the relationship of the failure stress of a coating (UES 300 with a base sublayer of brand 3132) in a weld-seam metal (Sv08GA steel) composite with a glass-enamel coating under conditions of cyclical creep at levels of up to ttest=6.105 sec. It was noted that below 448 K the failure stress of the coating over the metal of the weld seam is lower by 50–60 MN/m2 than in a composite with a base layer of a hot-rolled thick-sheeted 08GT-brand steel exhibiting greater ductility in tests of short duration, but under identical temperature conditions. The derived results are explained by the appearance within the weld-seam metal in contact with the coating of additional local stresses generated by volumetric changes within the process of residual austenite decay.