人们还普遍认为,只有二种适用于高速钢工具奥氏体化的保护气氛,也就是;露点至少为-45℃的干燥净化的放热气氛及露点低达-50℃的氨分解气氛。这些保护气氛是相当昂贵的。此外,它们对于随工具装炉而进入炉膛的即使是少量的空气也非常敏感。传统的吸热气氛的不适用性是 It is also generally accepted that there are only two protective atmospheres suitable for the austenitizing of high speed steel tools, that is, dry decontaminated exothermic atmospheres with a dew point of at least -45 ° C and an ammonia decomposition dew point as low as -50 ° C. These protective atmosphere is quite expensive. In addition, they are also very sensitive to even a small amount of air entering the hearth as the tool is loaded. Incompatibility of the traditional heat-absorbing atmosphere is