Study On Erosion Behaviors Of 316/304 Stainless Steel By Solid-Liquid Two Phase Flow Jet Impingement

Erosion wear exists in many engineering industries including hydraulic machinery,petrochemical industries,nuclear power stations and so on,which plays an important role in the process of degradation of pipe and equipment failure.It is very important to understand and grasp the mechanism of two-phase flow erosion,for which helping to reduce the failure of tubes and other components caused by erosion.The purpose of this thesis is to find the rule of multi-phase flow erosion for different conditions,and to explore the effect of NaCl solution corrosion on erosion of the sample.In thesis,the 24-hours long-term erosion behaviors of 304 stainless steel(304SS)and 316 stainless steel(316SS)by sand-water flow jet impingement were studied.The result shows that the weight loss of the sample reaches a maximum value at 45° impact angle,while when the impact angle comes to 75°,the weight loss reaches the minimum.The weight loss rates of 316SS/304 SS increase within 24 hours,but the increments decrease with time.The SEM photos show that,under the impact angle of 90°,there are several impact potholes on the surface of the sample.However,after the impingement of other smaller angles,the scratches appear on the surface of the sample.The smaller the angles,the more obvious the scratches.The possible reason is related to the different wear mechanisms under the different impact angles.When the impact angle is large,the main damage mechanism caused by the quartz sand particles is the frontal crash.However,when the impact angle comes to smaller,to the main damage mechanism is plowing.Two kinds of stainless steel samples were immersed in 3.5wt % NaCl solution and the erosion behaviors were studied.The results show that the weight loss rates of the 304 SS increase significantly under the normal impacting and 60° impacting.The weight loss rates of the 316 SS also increase,but the increments are much less than 304 SS.The impingement of the stainless steel samples experiments were carried out after the treatment by immersing in 3.5wt % NaCl solutions under 40 °C and 80 ℃,respectively.The weight loss rates of two kinds of stainless steel increase,but the increments of 304 SS are less than the increments of 316 stainless steel.