Proceedings of the Third International Conference on Metals & Hydrogen B01

Influence of Retained Austenite on the Hydrogen Diffusion in Martensitic-Ferritic Stainless Steel

D.C.S. Garcia (1)1(2)2 , R. N. Carvalho (1)1 , V. F. C. Lins (2)2 , D.S. dos Santos (3)3 , J. D. Ardisson (4)4

  • (1) 1

    Vallourec Soluções Tubulares do Brail, Olinto Meireles Avenue 65, Zip Code: 30640-010, Belo Horizonte, Brazil.

  • (2) 2

    Chemical Engineering Department, Federal University of Minas Gerais, Antonio Carlos Avenue 6627, Zip Code 31270901, Belo Horizonte, Brazil

  • (3) 3

    Federal University of Rio de Janeiro, PEMM/COPPE/UFRJ, PO-BOX 68505, 21941-972 RJ, Brazil

  • (4) 4

    Centro de Desenvolvimento da Tecnologia Nuclear, Antonio Carlos Avenue 6627, Zip Code 31270-010, Belo Horizonte Brazil.

Abstract

The effect of retained austenite on hydrogen permeation behavior was investigated by electrochemical hydrogen permeation technique developed by Devanathan-Starchuski. The samples were extracted from seamless stainless steel tube water quenched after a solution treatment at 1000°C for 30min and heat treated at different tempering temperatures in order to achieve different contents of retained austenite. As a result, the concentration of retained austenite (γret) in martensitic-ferritic stainless steel affected the hydrogen diffusion and the retained austenite morphology showed a significant effect on hydrogen permeation. The lower hydrogen apparent diffusion coefficient (Dapp) was obtained for the sample called high retained austenite (HRA) with 22% of γret and the high solubility was obtained for the sample called medium retained austenite (RA).

Introduction