Cross-section ovalization is one of the flaws in the thin-walled tube NC bending process.

截面畸变是薄壁管小半径数成容易出现的成缺陷之一。

The failure of directly buried heat-supply pipeline is discussed, and the design essentials are put forward in accordance with local buckling and ovalization deformation.

探讨了直管道的失效,针对局部失稳和椭圆化变,提出了设计要点。