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Influence of Nitrogen Solutes and Precipitates on Low Cycle Fatigue of 316L Stainless Steels Pages: 14 Published: Jan 1988
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View License Agreement Improvement of monotonic and cyclic mechanical properties of 316 steels by nitrogen is studied for different nitrogen contents between 0.03 and 0.25 wt% at 20 and 600°C. At 20°C, yield and ultimate tensile stress increase almost linearly with nitrogen content to the detriment of ductility. Low-cycle fatigue (LCF) life also increases linearly with nitrogen solutes until 0.12 wt% nitrogen where a saturation of this effect occurs. This improvement is attributed to a more homogeneous distribution and to a better reversibility of plastic strain. The influence of aging treatment at 600°C is studied on tensile and LCF properties at 20 and 600°C. An LCF life decrease with aging is more noticeable when nitrogen content is high. Furthermore, the higher the strain range, the more marked is the decrease in life at room temperature; this tendency is inverted at 600°C. At 20°C, stress evolution during the hardening-softening stage is virtually independent of aging time but strongly dependent on nitrogen content. For high strain ranges at 600°C and high nitrogen content, the stress increases continuously until rupture, due to significant intergranular precipitation and embrittlement. | ||
