Influence of nondestructive test procedures on detection of stress-corrosion cracks

A weld T joint from a scrapped carbon-steel digester level tank was used to test the efficacy of the nondestructive liquid-penetrant and magnetic-particle test methods commonly used for field detection of stress-corrosion cracks. The tests were conducted using three methods of surface preparation--wire brushing, light grinding, and sandblasting. Light grinding of the surface greatly increased the sensitivity of both the liquid-penetrant and magnetic-particle test methods. The most successful combination was light surface grinding followed by inspection with a fluorescent liquid.