利用中子衍射法和轮廓法测定GH4169圆盘残余应力

Determination of residual stress in GH4169 alloy disc by neutron diffraction method and contour method

分别采用中子衍射法和轮廓法对服役态GH4169合金圆盘工件内部残余应力分布特征进行表征。两种测试技术的机理完全不同,测量结果互相对比验证后,确定出较高可信度的残余应力测量结果。首先利用飞行时间中子衍射技术准确表征了GH4169合金圆盘完全热处理后轴向、径向和周向的应力,其量级约为-300~300 MPa,以周向和径向残余应力为主,沿轮廓呈“外压内拉”特征分布;利用轮廓法测量沿直径截面周向残余应力的二维分布图,切割截面周向残余应力呈现明显的“外拉内压”式分布特征的残余应力,残余应力量级约为-300~250 MPa量级。合金盘厚度中心截面上,中子衍射法与轮廓法的测试结果从趋势和绝对数值上基本一致,测试结果可信度高。

The distribution characteristics of residual stress of the GH4169 alloy disc parts on service were characterized by neutron diffraction method and contour method,respectively.The mechanism of two testing technologies was totally different.The measurements results were compared and verified to determine the value of residual stress with higher reliability.First,the stress in axial direction,radial direction,and hoop direction of GH4169 alloy disc after full heat treatment was accurately characterized by time-of-flight neutron diffraction technique.The residual stress level was about-300 to 300 MPa.The stress was mainly in the hoop direction and radial direction,showing the distribution characteristics of "External pressure and internal tension".Then,the two-dimensional(2 D) distribution map of residual stress in hoop direction along the cross section of dimeter was measured by contour method.The hoop residual stress in cutting section obviously showed the distribution characteristics of "external tension and internal pressure".The order of magnitude of residual stress was about-300 to 250 MPa.In the section of thickness center of alloy disc,the measuring results of neutron diffraction technique and contour method were basically consistent in both trend and absolute value.The reliability of measurement results was high.