Abstract
A systematic study was conducted of the effect of an oxygen environment on the
creep-fatigue failure of iron-<:hromium alloys at 600°C. The materials tested were ferrite steels containing up to 18 per cent chromium. namely low-carbon steel (no chromium), 3CR12 (12 per cent chromium), and 430 stainless steel (18 per cent chromium). The cyclic loading encountered creep tension and plastic compression according to the CP mode of the strain-range partitioning method under low-cycle fatigue conditions. The strain ranges varied from 0,2 to 0,45 per cent. The tested environments consisted of different mixtures of oxygen and argon, as well as an air atmosphere. The crack-growth behaviour was studied by scanning electron microscopy, EDAX analysis, and X-ray diffraction. The results showed that, when chromium was absent, as in the case of mild steel, the fatigue life was greater in argon than in air. The effect was reversed when 12 per cent chromium was present, as in the case of 3CR 12. The presence of 18 per cent chromium, as with 430 stainless steel, produced similar fatigue lives in argon and in environments containing up to 20 per cent oxygen.
creep-fatigue failure of iron-<:hromium alloys at 600°C. The materials tested were ferrite steels containing up to 18 per cent chromium. namely low-carbon steel (no chromium), 3CR12 (12 per cent chromium), and 430 stainless steel (18 per cent chromium). The cyclic loading encountered creep tension and plastic compression according to the CP mode of the strain-range partitioning method under low-cycle fatigue conditions. The strain ranges varied from 0,2 to 0,45 per cent. The tested environments consisted of different mixtures of oxygen and argon, as well as an air atmosphere. The crack-growth behaviour was studied by scanning electron microscopy, EDAX analysis, and X-ray diffraction. The results showed that, when chromium was absent, as in the case of mild steel, the fatigue life was greater in argon than in air. The effect was reversed when 12 per cent chromium was present, as in the case of 3CR 12. The presence of 18 per cent chromium, as with 430 stainless steel, produced similar fatigue lives in argon and in environments containing up to 20 per cent oxygen.
| Original language | English |
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| Title of host publication | INFANCON 6, Proceedings of the 1st International Chromium Steel and Alloys |
| Subtitle of host publication | Cape Town, South Africa |
| State | Published - 1 Jan 1992 |