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从离心铸造ＨＫ４０炉营上截取柱状晶方向与预制裂纹方向（炉管径向）呈不同角度（θ）的紧凑拉伸型试样，在８７１℃进行了恒载荷蠕变裂纹扩展试验。发现裂纹沿柱状晶方向扩展，而随θ角的增加，裂纹扩展抗力增大。θ角与裂纹扩展速率之间存在下列依赖性：ｄａ／ｄｔ＝Ａ［Ｋｃｏｓ￣２（θ／２））￣ｍ。裂纹扩展速率与能量率积分（Ｃ）的良好关联表明，Ｃ是铸态ＨＫ４０合金的蠕变裂纹扩展的控制参数。
A compact tensile specimen with a different angle (θ) in the direction of columnar grain from the direction of prefabricated crack (radial direction of the furnace tube) was cut from the centrifugal cast HK40 furnace camp and a constant load creep crack propagation test was carried out at 871 ℃. It is found that the crack propagates along the columnar grain, and as the angle θ increases, the crack propagation resistance increases. The following dependencies exist between the angle of θ and the rate of crack growth: da / dt = A [Kcos ~ 2 (θ / 2)) ~ m. The good correlation between crack growth rate and energy integral (C) shows that C is the control parameter for the creep crack growth of as-cast HK40 alloy.