(55c) Investigation of Erosion-Corrosion Behavior of 304 Stainless Steel Under Solid-Liquid Jet Flow Impinging at 30°

Yao, J., China University of Petroleum-Beijing
Zhao, Y., China University of Petroleum
This work used liquid-solid two-phase jet experiment to study the erosion behavior of 304 stainless steel at 30°impingement. It was found that after the test particles tended to become round with decreasing length-ratio and particle breakage occurred along the “long” direction. Due to particle-wall interaction, the total weight-loss of AISI 304 SS specimens decreased with time until reached constant state and particle size tended to distribute in small-size range. On the other hand, the averaged depth of grooves formed on the sample surface increased with impinging time until reached constant. Three kinds of wear-regions could be found in the sample after 30° impinging jet work, i.e. stagnation region, major transition region and wall jet region. Under the flow effect, the normal force dominated surface pits, the tangential force caused weight loss. In addition, after liquid impinging on AISI 304 SS sample, part of the austenite peaks (A) was found to transform to martensite peaks (M). 304 stainless steel erosion rate increased with temperature, where inter-granular corrosion cracking phenomenon was found to occur at the sample surface. Under the NaCl solution effect, 304 stainless steel sample pretreated at normal temperature, the surface became more easily damaged due to the effect of inter-granular corrosion cracking and grain peeling. At high temperature (300°C), the samples pretreated in NaCl solution had more inter-granular corrosion cracking and the particle-wall impact transformed part of austenite into martensite and ferrite (Fe-Cr).