A comparative study of thermal and hydraulic autofrettage

Abstract

Thermal autofrettage is a potential process to generate beneficial compressive residual stresses at and around the inner wall of a thickwalled cylinder for increasing its pressure carrying capacity. Due to its simplicity and inexpensive arrangement, it can compete with the conventional hydraulic autofrettage process. In this work, a comparative study of the thermal autofrettage and the hydraulic autofrettage is carried out. As the thermal autofrettage does not require hydraulic power pack, the process is more economical than the hydraulic autofrettage. The thermal autofrettage process is also studied for the thick-walled cylindrical vessels subjected to high thermal gradient with or without pressure and is compared with the hydraulic autofrettage. Comparison shows that for cylinders subjected to high thermal gradient without pressure, the thermal autofrettage is superior to the hydraulic autofrettage.

Parameter Sensitivity Analysis for Machining Operation of Autofrettaged Cylinder Using Taguchi Method

“…Hydraulic autofrettage, utilizing fluid pressure, and mechanical autofrettage, employing mandrels, are the two primary methods used to enhance the pressure-bearing capacity and fatigue life of cylinders. Widely adopted across industries like aerospace, automotive, and pressure vessel manufacturing, autofrettage significantly improves the durability and safety of high-pressure components [1][2][3][4][5][6][7].…”

Aplicación del proceso de swaging para la generación de tensiones residuales en componentes sometidos a altas presiones

“…Ya en 2016, Kamal et al [62] realizaron un estudio comparativo entre el autozunchado térmico e hidráulico asumiendo propiedades independientes de la temperatura y mostraron que el incremento alcanzable de la capacidad de contención de la presión mediante autozunchado térmico era inferior que la alcanzable mediante autozunchado hidráulico debido al límite de temperatura alcanzable para evitar la recristalización del material. También en 2016, Kamal et al [63] realizaron un estudio experimental para la investigación de las tensiones residuales inducidas en un cilindro por autozunchado térmico.…”