Mechanical Properties of UNS S39274 Superduplex Stainless Steel Work Hardened and Solution Annealed

Abstract

Abstract UNS S39274 is a W-alloyed superduplex stainless steel used in critical services in the oil and gas production. This material was selected for tubullars used in oil country tubular goods, below the Christmas tree. In order to achieve high mechanical strength the seamless tubes are cold drawn in a costly operation. In this work the mechanical properties of a cold drawn seamless were characterized and compared to three solution treated materials. Tensile curves were obtained and modelled by Hollomon’s, Ludwik’s and Voce’s models, where the last one presented the higher correlation coefficients in all cases. The hardness and impact toughness at -46oC were measured and discussed. The results were analyzed taking into aconunt the microstructural changes produced by cold drawning and annealing.

Keywords

• superduplex stainless steel
• solution annealing
• mechanical properties