Abstract Study results of the effect of high-temperature vacuum chemical-thermal treatment on the grain size of structural steels possessing various chemical compositions are given. It is determined that a sufficiently large grain is formed in the 20KhN3A, 25KhGT, and 20KhNR steels during quenching directly after prequench from the carbonization temperature of 1000–1050 to 850°C, whose size exceeds acceptable limits. It is stated that the steels manufactured according to GOST 4543–2016 are inapplicable for high-temperature carbonization. The composition of new inheritable fine-grained steel is developed, which is not affected by the increase in the carbonization temperature. An increase in the carbonization temperature of new steel up to 1050°C with a double decrease in the time of treatment is demonstrated.

中文翻译：

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高温碳化用钢

摘要 给出了高温真空化学热处理对各种化学成分结构钢晶粒尺寸影响的研究结果。确定在 20KhN3A、25KhGT 和 20KhNR 钢从碳化温度 1000-1050 至 850°C 预淬后直接淬火过程中形成了足够大的晶粒，其尺寸超出了可接受的范围。据称，根据 GOST 4543-2016 制造的钢不适用于高温碳化。开发了新的可继承细晶钢成分，不受碳化温度升高的影响。新钢的碳化温度升高到 1050°C，同时处理时间双倍减少。