ABSTRACT The article presents the results of research on the precipitation processes in austenitic T321H steel in the as-received state and after around 207,000 h of service under the creep conditions at the temperature of 540°C. The tests performed on the T321H steel showed that during long-term service the precipitation of G phase and sigma phase occurred and those phases precipitated at the cost of M23C6 carbides. The preferential place of precipitation of the phases was the boundaries of grains, and in the case of sigma phase – the triple points at grain boundaries. After long-term service, the sigma phase was the dominant precipitate in the examined steel. Inside the grains, both in the as-received state and after long-term service, the TiX and TiC precipitates were observed. The following precipitation sequence for austenitic T321H steel can be suggested:

中文翻译：

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使用 207,000 小时后钛稳定奥氏体不锈钢的沉淀研究

摘要 本文介绍了奥氏体 T321H 钢在 540°C 温度下蠕变条件下使用约 207,000 小时后在原样状态下的析出过程的研究结果。对 T321H 钢进行的测试表明，在长期使用过程中，发生了 G 相和 σ 相的析出，这些相以 M23C6 碳化物为代价析出。相的优先析出位置是晶粒边界，而在 σ 相的情况下，则是晶粒边界处的三相点。长期使用后，σ 相是受检钢中的主要析出物。在晶粒内部，无论是在接收状态还是在长期使用后，都观察到 TiX 和 TiC 析出物。