基于轮廓法测试镍基高温合金惯性摩擦焊接头内部残余应力

采用轮廓法(contour method)测试小直径FGH96镍基高温合金惯性摩擦焊接接头的内部环向应力。详细介绍了轮廓法测试步骤,包括试样切割、切割面轮廓测试、数据处理和有限元分析;获得了FGH96镍基高温合金惯性摩擦焊接接头内部环向应力分布全貌并分析其分布特征。测试结果表明:镍基高温合金惯性摩擦焊接接头的焊缝中心位置环向应力为非常大的拉应力,峰值拉应力为1200 MPa,达到材料室温时的屈服强度;焊缝区域(距焊缝中心±5 mm区域)近内壁区域的环向应力大于外壁区域环向应力,垂直焊缝方向的环向应力变化梯度非常大;远离焊缝区域,焊缝两侧的环向应力不对称。

Experimental Measurement of Internal Residual Stress in Nickel-Base Superalloy Inertia Friction Weld Using the Contour Method

The internal hoop residual stress in FGH96 nickel-base superalloy inertia friction weld with small diameter was measured using the contour method. The measuring procedure including specimen cutting, contour measurement, data processing and finite element analysis was introduced. The full map of the internal hoop residual stress within the nickel-base superalloy inertia friction weld was obtained with the proposed method and the hoop residual stress distribution characteristics were also analyzed. The results show that the tensile hoop residual stress of nickel-base superalloy inertia friction weld at the weldline center is very large with a peak value of 1200 MPa, which almost equals to the yield strength of the material at room temperature; within the weld zone (±5 mm distance from the weldline center), the tensile hoop residual stress at the region near the inner diameter of the wall is larger than that near the outer diameter of the wall, and the hoop residual stress gradient in the direction perpendicular to the weld line is very steep; far from the weld zone, the hoop residual stress at the both sides of the weld demonstrates an asymmetric distribution