冷却速率对MarM247铸造合金组织及拉伸性能的影响

Effect of Cooling Rate on Microsturcsture and Tensile Properties of Mar M247 Cast Alloy

通过研究定向凝固Mar M247合金冷却速率和显微组织,显微组织同拉伸性能间的关系,推导出合金冷却速率同拉伸性能间的关系。结果表明,冷却速率0.15~2.00℃/s,随着冷却速率的增加,合金二次枝晶臂间距(λ^(2))、最大碳化物尺寸(C_(1))和共晶平均尺寸(E_(4))逐渐减小,且分别满足λ_(2)=42.68·^(■-0.2548),C_(1)=-22.95·log■+38.59,E_(4)=-11.21·log■+26.88关系式。而相同浇铸温度(1480℃)和模组结构,不同模壳温度(950℃、1000℃、1100℃、1180℃)试验浇铸所得铸件合金组织(二次枝晶臂间距、最大碳化物尺寸和共晶平均尺寸)同其屈服强度和抗拉强度也呈负相关关系。借助合金组织特征参数推导出的冷却速率和拉伸性能关系式,为利用冷却速率评估、计算铸件力学性能提供了参考。

The relationship between the cooling rate and tensile properties of Mar-M247 alloy was deduced by studying the cooling rate、microscopic structure and tensile properties.The results showed that,in the range of 0.15℃/s~2.00℃/s,with the increase of the cooling rate,the secondary dendrite arm spacing(λ_(2)),maximum carbide size(C_(1))and common crystal mean size(E_(4))wereλ_(2)=42.68·■^(-0.2548),C_(1)=-22.95·log■+38.59,E_(4)=-11.21·log■+26.88,respectively.Different mold shell temperatures(950℃,1000℃,1100℃,1180℃)of casting alloy structure were also negatively correlated with their yield strength and tensile strength with the same casting temperature(1480℃)and module structure.The relationship between cooling rate and tensile properties derived from the characteristic parameters of the alloy structure provides a reference for evaluating and calculating the mechanical properties of castings.