Study On The Erosion-corrosion Of A New Duplex Stainless Steel For Flow Passage Component In Phosphate Slurry

The flow path components in phosphate slurry are made of duplex stainless steel with excellent resistance to pitting corrosion and erosion,by the control of the design of the novel materials's ingredients and its heat treatment process,we had achieved the ferrite and austenite two-phase concentration close to 1:1.A typical duplex stainless steel 2205 used in the flow path components was selected to compare with.Based on preparation of materials and their erosion resistance,which had been researched by the use of wear testing machine with liquid-solid dual phase erosion.the erosion resistance and failure mechanism of two materials were studied.It was concluded that:(1)The content of the austenite and ferrite in 00Cr22Ni6MnMoCu is close to 1:1. In addition,00Cr22Ni6MnMoCu has distribution organizations and comprehensive mechanical properties.(2)The corrosion-resistant properties of new materials 00Cr22Ni6MnMoCu is 1.7 times of duplex stainless steel 2205's;electrolytic corrosion experiment had showed that the corrosion failure of 00Cr22Ni6MnMoCu are mainly intercrystalline corrosion with a small hole corrosion,while the corrosion failure of 2205 is a small hole corrosion.(3)The erosion resistance of 00Cr22Ni6MnMoCu is about 1.3 times higher than DSS 2205,and the failure mechanism of the former's erosion cutting and plowing were short,shallow,and in a certain direction,and its number is also small,and the erosion failure of 2205 is mainly cutting and plowing,in addition,it also had a lot of long and fine scratch marks with scratches clear direction and a small amount of corrosion.(4)The change that the hardness of subsurface and phase of test materials showed that the distortion strengthening of new material is more complete than the 2205,which is an important reason for its superior anti-erosion;A large volume fraction difference of ferrite and austenite phase and too much content of ferrite produce a great interphases stress during erosion,thus,it results in toughness decrease and poor erosion resistance.