过去,超硬合金中强度最高的都是些铁基合金,但后来就被高温性能更为优越的钴基合金和镍基合金所代替。然而选用耐热合金时,除了要考虑它们的强度和抗氧化性能外,还要考虑到工作环境和工作条件。例如,镍基合金就不适用于可能受硫侵蚀的场合;这会引起脆化现象,并且使工件迅速损坏。合铬较高的合金,在高真空条件 In the past, some of the highest strength cemented carbide alloys were iron-based alloys, but were later replaced by cobalt-based alloys and nickel-based alloys with superior high-temperature properties. However, the selection of heat-resistant alloys, in addition to considering their strength and oxidation resistance, but also taking into account the working environment and working conditions. For example, nickel-based alloys are not suitable for applications that may be attacked by sulfur; this can cause embrittlement and cause rapid damage to the workpiece. Chromium alloy higher, in high vacuum conditions