钴基合金是在钴铬合金中熔入适量的钨和碳,钨的加入使钴基体进一步固溶强化。碳在钴中的溶解度很小,因而加入的碳和过量的钨形成 WC,W2C,M6C等碳化物,这些硬质相弥散分布在钴基体中,产生析出强化作用,使该类合金在800℃高温下,仍能保持优异的高温强度和高温硬度,因此钴、铬、钨、碳合金具有优异耐高温磨损、抗高温氧化和热疲劳等综合性能。
Cobalt-base alloy is produced by melting suitable amount of tungsten and carbon into the cobalt-chrome alloy, which will enhance the solid-solution strengthening of the cobalt base. For the low solubility of carbon in cobalt, the added carbon and superfluous tungsten may generate WC,W2C,M6C and other carbides. The hard materials distribute in the cobalt base and strengthen the separation process, thus the alloy can maintain excellent intension and rigidity under high temperature of 800℃. Thus, the cobalt, chrome, tungsten and carbon alloy have integrated performance of preventing the high temperature wear, oxidation and thermal fatigue.
钴在417℃温度以下,为密排六方结构,具有低的摩擦系数,而具有很好的耐磨性。在417℃温度时发生由密排六方晶体,向面心立方晶体的转变,而产生体积应力。因此在喷焊时一般均需将被焊工件预热到500℃~600℃,以防钴基焊层开裂。