退火套合残余应力的计算模型及试验研究

Calculation model and experimental research on residual stress of annealed shrink fit

为了从理论上指导退火消除套合筒体的套合应力,推导出套合残余应力衰减模型。采用一次切削残余应力释放方法,测量筒体退火前、退火后内外壁面的残余应力沿圆周和轴向的变化,来验证残余应力的衰减规律。试验显示套合预应力理论计算误差在10%以下;外筒外壁平均残余应力测量值为48 MPa,衰减率为61%,而模型预测数值为23 MPa,预测衰减率为79%;内筒内壁平均残余应力测量值为-28 MPa,衰减率为73%,而模型预测数值为-23 MPa,预测衰减率为78%。结果表明,该退火消除套合应力的计算模型,可作为套合筒体退火去应力工艺的理论依据;套合容器必须进行消除或降低套合预应力的退火热处理。

In order to guide the annealing process theoretically to eliminate the residual stress of shrink fit cylinder,the decay calculation model of shrink fit residual stress was deduced. Method of releasing residual stress by one time cutting was used to measure the residual stress in internal and external wall along the circumferential and axial direction,to verify the attenuation of the residual stress. Test shows that theoretical calculation error of original shrink fit stress is less than 10%; the measured residual stress in external cylindrical outer wall is48 MPa,the attenuation rate 61%,while the predicted value is 23 MPa,the predicted attenuation rate 79%; the measured residual stress in internal cylindrical inner wall is- 28 MPa,the attenuation rate 73%,while the predicted value is- 23 MPa,the predicted attenuation rate78%. The residual stress decay model for annealing to eliminate the shrink fit residual stress can be used as a theoretical guideline for shrink fit cylinder; shrink fit containers must be annealed to eliminate or reduce the original shrink fit stress.