【摘要】 本文研究了15Cr-25Ni和15Cr-40Ni型铁基高温合金中μ和σ相引起的晶界脆化。在铁基高温合金中当晶界存在少量的μ和σ相时(甚至其含量在0.01—1%间),就会引起合金脆化,其脆化程度与晶界存在的μ和σ相的密集系数成正比关系。冲击试验时的脆化导致沿晶断裂,μ和σ相所引起的断裂机构是完全不同的。减小晶粒尺寸或控制合金化学成分使晶界上的μ和σ相减少或根本不生成,则可以控制或消除合金的脆化效应。更多还原

【Abstract】 Grain boundary embrittlement by μ and σ phases was studied in 15Cr-25Ni and 15Cr-40Ni type iron-base superalloys. The embrittlement of iron-base superalloys can be sensitive to small amounts of μ and σ phases present at the grain boundaries, even when the weight fraction is between 0.01 and 1%. The degree of embrittlement was found to be directly proportional to the concentration coefficients of the μ and σ phases at the grain boundaries. The embrittlement effect results in intergranular fracture during impact testing. Fracture mechanisms caused by the μ and σ phases were quite different. This embrittlement effect was suppressed by reducing the grain size or by decreasing or removing the grain boundary embrittling μ and σ phases by controlling the chemical composition of the alloys.更多还原