Nitrogen is a well-known gamma-stabiliser in austenitic steels, also responsible for significant solid solution hardening of these materials. Yet, only few papers have studied its impact on austenitic high-entropy alloy (HEA) matrixes. This study focuses on a cobalt-free, non equimolar CrFeMnNi HEA doped with nitrogen. A series of alloys was cast under a nitriding atmosphere to promote nitrogen absorption into the liquid alloy. Study of as-cast alloys has shown nitrogen presence in solid solution up to 0.3 wt % (1.2 at. %). Over the whole range of compositions, a linear increase of hardness (134 HV/wt. % of N) was measured as well as an expansion of the lattice parameter of Δa/a = 1.01/wt. % N due to nitrogen addition in the interstitial sites of the lattice. Tests on forged and annealed samples showed that the increase of hardness with nitrogen addition is higher than in as-cast state (210 HV/wt. % of N) surely due to presence of other strengthening mechanisms. Tensile tests confirmed that the presence of dissolved nitrogen increases yield strength and ultimate strength and enhances strain-hardening, without any modification of ductility.

氮是奥氏体钢中众所周知的伽马稳定剂，还可以使这些材料显着固溶硬化。但是，只有很少的论文研究了其对奥氏体高熵合金（HEA）基体的影响。这项研究的重点是掺氮的无钴，非等摩尔CrFeMnNi HEA。在氮化气氛下铸造一系列合金以促进氮吸收到液态合金中。对铸态合金的研究表明，固溶体中氮的含量最高为0.3 wt％（1.2 at。％）。在整个组成范围内，测得硬度线性增加（N为134 HV / wt。％），晶格参数的扩展为Δa/ a = 1.01 / wt。由于氮在晶格的间隙位置中的添加而导致的％N。对锻造和退火样品的测试表明，固氮的硬度增加比铸态（210 HV / wt。％N）要高，这归因于存在其他强化机制。拉伸试验证实，溶解氮的存在增加了屈服强度和极限强度，并增强了应变硬化，而没有任何延展性的改变。