Study On Failure Behavior Of Impact Corrosion Wear Of Cr30A Used In Desulfurization Circulating Pump Overflow Parts

Desulfurization circulating pump is in a state of reduced service life cause the effect of corrosive wear.To better provide a theoretical basis for the rapid failure of the desulfurization circulating pump in thermal power plants,and to offer scientific basis for scientific selection and optimized operation process of key components for desulfurization,in this paper,which deals with the phenomenon of corrosion and wear under desulfurization conditions,Cr30A alloy is studied as the research obJect,the corrosive wear behavior of the Cr30A alloy under different impact of overflow parts is discussed systematically with the method of weight loss,scanning electron microscope and energy dispersive spectrometer by self-made corrosive wear tester.The main work and results of the paper are as follows:The mechanism of impact corrosive wear is discussed through the impact corrosive wear test of Cr30A under different overflow parts of impact environment.The Cr30A,when as the flow wall material in the near parallel impact environment,the impact corrosive wear weight loss rate of Cr30A increases with the increase of the rotational speed.When the speed is 1500 r/min,the quality loss of the material suffered from corrosion and wear is the most serious.The impact corrosive wear mechanism of Cr30A alloy is mainly micro-cutting.As the impeller material in the low angle impact environment,when the rotation speed is low,the impact corrosive wear mechanism of Cr30A is mainly based on cutting and plowing.The impact corrosive wear mechanism at high rotational speed is mainly extrusion rib fracture and shallow layer flaking caused by fatigue crack propagation.As a pump casing material in the high-angle impact environment,when the rotation speed is low,the impact corrosive wear mechanism of Cr30A is mainly plowing and corrosive wear,the impact corrosive wear mechanism at high speed is mainly due to the deep large pieces falling off and the serious corrosive wear.As a protective material in the near vertical impact environment,the impact corrosive wear mechanism of Cr30A is mainly the small piece falling off and corrosive wear of the material.There is a significant interaction between Cr30A corrosion and wear in corrosive slurries under different impact conditions of overflow parts.As the flow wall material in the near parallel impact environment,The weight loss of Cr30A impact corrosive wear mainly comes from corrosion,and its interaction accounts for 11.65%-39.18%of the total damage.As a impeller material under the impact of small angle,the interaction of Cr30A impact corrosive wear accounted for 41.86%～53.67%of the total damage,when the speed was 1500 r/min,the weight loss of impact corrosive wear is mainly come from the interaction.As a pump casing material in the high-angle impact environment,the weight loss of Cr30A impact corrosive wear mainly comes from the interaction of corrosion and wear,and the interaction accounts for 55.30%～67.28%of the total abrasion amount.As a protective material in the near vertical impact environment,the interaction of Cr30A impact corrosive wear accounted for 18.84%-44.51%of the total abrasion amount.The interaction is related to the impact environment and the speed.The interaction mechanism is summarized as follows:The material is plastically deformed by impact to form a strain difference battery,which promotes corrosion.The material is cracked by repeated impacts,and the corrosive medium penetrates into the crack to cause the material to fall off,and corrosion promotes wear.