Examination of Pipe Wall Thinning Phenomenon by High Temperature Impact Fretting Testing (Development of a Test Rig and Screening of Effective Factors)

Abstract

In this paper, to study the wear properties of the pipe materials for the nuclear power stations, a high temperature impact fretting test rig was developed. Employing two piezo actuators, this rig can generate impact fretting under various impact loads, fretting amplitudes and frequencies. It also enables us to control water temperature, dissolved oxygen and water pressure. AISI type 304 stainless steel, which is used as a pipe material in nuclear power stations, was used as specimens. Alumina balls were used as the counter materials. Wear property under impact fretting was severer than that under pure fretting and pure impact. The experiment according to L₁₈ orthogonal table has shown that wear was strongly affected by the chemical factors. Especially, water temperature and frequency were significant in the analysis of the wear depth.