Magnetic Testing of Stressed State of Hydrotested Gas-Separator Wall

Abstract

The stressed state of a hydrotested gas separator has been studied by magnetoelastic demagnetization. Correlation dependences are obtained between the level of magnetoelastic demagnetization of a complex-loaded gas-separator wall and the magnitude of hoop, meridian, and equivalent stresses it experiences. The magnetoelastic demagnetization of a residually magnetized test-object wall, loaded with internal pressure, was estimated from the change in the strength of its magnetic stray field measured along the normal (H_n) and tangent (H_τ) to the surface. It has been established that the growth of mechanical stresses in the separator wall to half the value of the yield strength of steel it is made of causes a noticeable irreversible decrease in the normal (H_n) and tangential (H_τ) components of the strength of its magnetic stray field in the residually magnetized area. It is shown that the method of magnetoelastic demagnetization has the highest sensitivity to mechanical stresses and is easiest to implement and most prompt compared with coercimetry and tensometry.