Experimental and Theoretical Analysis of Zircaloy-4 and AISI 304 Stainless Steel Material Pair in Water Sliding Conditions

Abstract

Current work was simulated for sliding wear interaction of materials of fuel bundle bearing pad (zircaloy-4) and magazine rotor tube (AISI 304 stainless steel) of Indian Pressurised Heavy Water Reactors (PHWRs). A plan of experiments, based on the techniques of Taguchi, was performed. The objective was to establish a correlation between load and sliding speed with the volume loss and coefficient of friction (COF). These correlations were obtained by multiple linear regressions. The treatment of the experimental results is based on the analysis average and the analysis of variance (ANOVA). Worn surface analyses carried out using SEM and wear mechanisms were identified. ANOVA analysis indicated that load factor has a great influence on the coefficient of friction (∼73%). COF suddenly increases to high value after a particular contact pressure due to absence of lubricating film and increase in metal to metal contact. Volume loss of AISI 304 stainless steel and zircaloy-4 is highly affected due to load (∼90%) and speed (∼65%), respectively. Worn surfaces exhibited deformation, adherence, and compaction of material at all PV conditions. Contact pressures above 475 MPa indicated formation of ratcheting mechanisms and formation of fatigue striation marks. Due to low yield strength of AISI 304 SS, volume loss was on higher side than that of Zr-4.

The correlation between friction coefficient and areal topography parameters for AISI 304 steel sliding against AISI 52100 steel

“…It has been mentioned in Refs. [30,31] that f increases with an increase in load. In dry contact, at lower load, oxide layer formed which protected direct asperityto-asperity contacts.…”

“…Oxide layer breaks at higher load leading to severe abrasive or adhesive depending on the material combination, hardness, and composite surface roughness [31]. In past, the effect of normal load on f has been discussed in detail [30,31]. In this section, wear mechanisms involved for obtaining higher friction at higher load and the evolution of topography parameters with sliding time for friction tests are discussed in detail.…”