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以JIS SUS 304和SUS 304N为实验材料,在应力控制条件下研究了两种奥氏体不锈钢的低周疲劳性能.结果表明:（1）在低应力区（σa<430 MPa）,SUS 304N的疲劳寿命高于SUS 304的疲劳寿命;但在高应力区（σa>430 MPa）,静强度较高的SUS 304N的疲劳寿命反而低于SUS 304的疲劳寿命.（2）SUS 304中疲劳微裂纹萌生的循环次数比远小于SUS 304N.在低应力区,SUS 304中的疲劳微裂纹萌生后。其扩展速率大于SUS 304N;但在高应力区,SUS 304中的疲劳微裂纹萌生后,其扩展速率小于SUS 304N,使它在高应力区的疲劳寿命超过了SUS 304N.（3）添加氮元素后.奥氏体组织的稳定性得到提高.疲劳实验过程中SUS 304发生了显著的应变诱发马氏体转变,而SUS 304N基本未发生此现象.
The low cycle fatigue properties of two austenitic stainless steels were studied under the stress control conditions using JIS SUS 304 and SUS 304N as experimental materials.The results show that: (1) In low stress zone (σa <430 MPa), SUS 304N The fatigue life is higher than that of SUS 304. However, the fatigue life of SUS 304N with higher static strength is lower than that of SUS 304 in the high stress region (σa> 430 MPa). (2) Fatigue microcracks in SUS 304 The number of cycles of initiation is much less than that of SUS 304 N. In the low stress zone, the fatigue crack initiation in SUS 304 occurs. Its rate of expansion is greater than SUS 304N. However, in the high-stress zone, the fatigue crack growth rate of SUS 304 after fatigue micro-crack initiation is less than SUS 304N, which leads to its fatigue life in high stress area exceeds that of SUS 304N. (3) , The stability of austenitic structure was improved.No significant strain-induced martensitic transformation occurred in the SUS 304 during the fatigue test, but this phenomenon did not occur in the SUS 304N.