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component(s) have not been identified, but should be found so as to minimize the likelihood of any
future fractures.
The pins had been heat treated to give a hardness in the range HRC 46-47. Although this was
only slightly higher than the hardness specified, it brought the steel to within the HE susceptibility
range.
Hydrogen embrittlement can be avoided by :
(i) Removing the source of hydrogen.
(ii) Reducing the strength of the steel.
(iii) Using a steel that is more resistant to HE.
Before any recommendations can be made for a suitable hardness, and thus heat treatment
schedule for future pins, more details of the operating stresses are required.

Acknowledgement-This paper is published by permission of Mintek.

REFERENCES
1. Kemp, M. S. and van Bennekom, A., Stainless Steel, 1995,16.
2. Engel, L. and Klingele, H., An Atlas at MefalDamage. Wolfe Publication Ltd, London, 1981.
3. ASM Handbook, 4, ASM International, 1991.
4. Ning, L., Zhonggang, D. and Mengen, H., Materials Science and Technology, 1991,7, 1058.
5. Metals Handbook, Vol. 10,8th edn. ASM International, Ohio, 1975.
6. McIntyre, D. R., in Process Indwtries Corrosion, ed. B. J. Muniz, W. I. Pollock. NACE, Houston, 1986.
7. Sedriks, A. J., Corrosion ofSfainless Sleek. Wiley-Interscience, New York, 1979.
8. Thompson, A. W. and Bernstein, I. M., in Advances in Corrosion Science and TechnoIogy, Vol. 7, ed. M. G. Fontana and
R. W. Staehle. Plenum Press, New York, 1980.
9. Warren, D., in Process Industries Corrosion, ed. B. J. Muniz, W. I. Pollock. NACE, Houston, 1986.