(太原理工大学表面工程研究所，太原 030024)
摘 要: 研究了W, Co, Ni对时效合金强度和韧性的影响。结果表明：高Co的Fe-W-Co合金有强的时效硬化能力，但其韧性较低。以Ni取代部分Co之后，合金的韧性得到大的提高。Fe-W-Co合金的Co量约23%，W, Mo总量超过18%时，硬度增加甚少，韧性损害较大，而Fe-W-Co-Ni的Co当量达23%，W, Mo总量达24%时获得最佳的强度和韧性的配合。萃取化合物的X射线衍射(XRD) 分析表明，时效合金的主要金属间化合物是Fe3W2型，还有Fe7W6和Fe2W型化合物。 淬火态、退火态萃取物的化学分析表明，时效合金中，W, Mo主要存在于化合 物中 ，而Co, Ni主要存在于固溶体中。时效硬化主要通过W, Mo金属间化合物的析出引起。而Co, Ni主要通过影响析出相的数量、析出物形态及分布状态来影响时效硬化
关键字: 强度 韧性 固溶体 金属间化合物 时效硬化
（Research Institute of Surface Engineering,Taiyuan University of Technology, Taiyuan 030024, P. R. China）
Abstract:The influence of W, Co and Ni on strength and toughness of ageing alloys was studied. The results indicated that the Fe-W-Co alloy with higher cobalt possesses stronger ability of age-hardening but lower toughness. After cobalt is partly substituted by nickel, the toughness of alloy is greatly raised . The hardness almost doesn't increase and toughness decreases greatly, when the total content of (W+Mo) is over 18% in Fe-W-Co alloy with 23% Co, but when the cobalt equivalent reached 23% and the total quantity of W and Mo reaches about 24% in F e-W-Co-Ni alloy, the optimum combination of strength and toughness is obtained. X-ray d iffraction (XRD) result for extraction compounds showed that Fe3W2 type is the main intermetallic compound in ageing alloy, and there are also compounds of Fe7W6 type and Fe2W type. The chemical analysis of extraction compounds showed that the majority of W and Mo exists in compounds, while the majority of Co and Ni exists in solid solution. The age-hardening is mainly caused by deposition of intermetallic compounds of W and Mo. Co and Ni have an effect on age-hardening mainly through affecting quantity, shape and distribution of precipitation phases.
Key words: strength toughness solid solution intermetallic compounds agehardening
