Low alloy steels for use in H(2)S medium : Means of improving the behaviour of high elastic limit steels
Project ID: 7210-KE/305Funded under: ECSC-STEELRES 7C
The aim is to determine how the behaviour of low alloy steels with high elastic limits for use in an H(2)S medium can be improved. Two possibilities have been considered: the use of normalised steel enriched with alloys and micro-alloys to limit carbon content, and the use of quenched and tempered steels (type E500). The results of this research have shown that using quenched and tempered steels can have a number of advantages: increased resistance to SSC, better resistance to crack propagation, good resistance of the bainitic structure to HIC. However, it was also shown that segregation can have a harmful effect. The negative role of phosphorus was again demonstrated. Nevertheless, it seems that reducing the Ceq content can reduce the harmful effect of segregation. Tests on welded structures showed that quenched and tempered steels have a level of behaviour in the HAZ at least equivalent to that obtained with normalised steels. Again, proper balance of the chemical composition of quenched and tempered steels should make it possible to guarantee very good behaviour in the HAZ resulting from low hardness levels. The electrochemical permeation tests have shown the role played by chemical composition and microstructure on the diffusivity and entrapment of hydrogen.
Bibliographic Reference: EUR 14355 FR (1993) 74 pp., FS, ECU 9
ISBN: ISBN 92-826-5069
Record Number: 199310406 / Last updated on: 1994-11-29
Original language: fr
Available languages: fr