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本文根据小型氮化炉的制造和使用经验,对氮化炉的结构上和操作上的几个问题进行了分析。实践和理论分析证明,炉罐和夹具必须加防护涂料,否则将使氨分解率大为增加,使氮化过程难以控制。在无风扇的炉子中,应以合理装料、适当供气、排气和采用特殊夹具等方法来提高气流速度,迫使炉气均匀流过所有氮化表面,使氮化效果一致。某些小型氮化炉采用橡胶圈密封炉门有较好效果。可将废气通入适当炉子中使残氨和HCN气体分解,以消除公害和存在有CO_2时防止形成(NH_4)_2CO_2阻塞管路。文中还介绍了气体软氮化时的适当管路系统和供气、排气和混合装置。通过计算证明,氮蒸发气体中的最大含水量通常在1.7％以下,与液氨含水量无直接关系,一般不致于引起工件氧化。因此,氮化用氨一般没有必要进行干燥处理。
Based on the experience of manufacture and use of small nitriding furnaces, this paper analyzes the structural and operational problems of nitriding furnaces. Practice and theoretical analysis have proved that furnaces and fixtures must add protective coatings, or ammonia decomposition rate will greatly increase the nitriding process is difficult to control. In fan-free furnaces, airflow should be increased by proper charging, proper air supply, venting, and special fixtures to force the furnace gas to flow evenly across all nitrided surfaces to achieve the same nitriding effect. Some small nitriding furnace rubber ring seal door with good results. Exhaust gas can be passed into an appropriate furnace to decompose residual ammonia and HCN gas to eliminate pollution and prevent formation of (NH_4) _2CO_2 obstruction in the presence of CO_2. The article also describes the appropriate piping system for gas nitriding and gas, venting and mixing devices. It has been proved by calculation that the maximum water content in the nitrogen evaporation gas is usually below 1.7%, which is not directly related to the liquid ammonia content and generally does not cause the oxidation of the workpiece. Therefore, nitriding with ammonia is generally not necessary for drying.