一种大口径薄壁不锈钢风洞收缩段曲面加工方法

A method for machining the curved surface of the contraction section of large-diameter thin-wall stainless steel wind tunne

收缩段是高速风洞的重要组成部分,收缩段曲面型面精度对高速风洞的流场品质影响较大。某特种风洞收缩段采用不锈钢材质,其流道为7 m量级入口的大口径薄壁高精度曲面,收缩段壁厚较薄,筋板稀疏,整体刚度弱,加工易变形。经过工艺研究,探索出了一种采用涂层刀片、差异化切削参数、分区域交替法向加工、在线监控和样板测量相互验证形变的工艺方法,不仅保证了型面精度要求,而且大幅提升了工效,成功解决了大口径不锈钢薄壁收缩段高精度曲面加工的难题。

The contraction section is an important part of the high-speed wind tunnel.The surface accuracy of the contraction section has a great impact on the flow field quality of the high-speed wind tunnel.The contraction section of a special wind tunnel is made of stainless steel.Its flow channel is a large-diameter,thin-walled and high-precision curved surface at the inlet of 7 m.The wall thickness of the contraction section is thin,the ribs are sparse,the overall stiffness is weak,and the processing is easy to deform.Through process research,a process method of mutually verifying deformation by using coated blade,differentiated cutting parameters,zonal alternating normal machining,on-line monitoring and sample measurement is explored,which not only ensures the requirements of profile accuracy,but also greatly improves the work efficiency,and successfully solves the problem of high-precision surface machining of thin-walled shrinkage section of large-diameter stainless steel.