外热式坩锅硝盐炉是高速钢刀具淬火后进行回火处理的重要加热设备。它具有加热速度快、温度均匀和不易氧化等优点。然而,在长期的生产中,外热式坩锅硝盐炉电阻丝常容易断损,即使新更换的电阻丝,使用寿命也不长(最多2—3个月)。经过我们仔细观察,发现回火工件装炉和出炉频繁,往往把一定数量的硝盐液(硝酸钾和硝酸钠)带溅在炉盖上,炽热的硝盐液顺着炉盖和炉壳上部的缝隙及接线 Exothermic crucible nitrate salt furnace is a high-speed steel tool quenching after tempering an important heating equipment. It has a heating speed, temperature uniformity and easy oxidation. However, in the long-term production, the outer crucible salt furnace resistance wire is often easily broken, even the newly replaced resistance wire, the service life is not long (up to 2-3 months). After careful observation, we found that tempering workpieces were frequently loaded and unloaded. A certain amount of nitrate solution (potassium nitrate and sodium nitrate) was often splashed on the furnace lid. The hot nitrate solution followed the furnace lid and the upper part of the furnace shell The gap and wiring