Research On Designing The Structure Of The Large-Sized Valve And Corrosion-resisting Of The Surfacing Layer

Every year the leakage of the valves cause a seriously loss of property and life, thesituation damaging the life, have occurred from time to time. The cause of valve leaking inthe chemical industry, one of the two reasons is that switch malfunction, In view of thissituation, This paper describes the design of a double control switch, it increased its safety,another cause for the leakage is the for the long time corrosion by the internal solution. Forexample by the long-time corrosion of the H2SO4、H3PO4、HNO3the situation mentionedabove will happen, as is known to all, austenitic stainless steel has the good corrosionresistance. for example the super austenitic stainless steel, But its price is too expensive,especially on some big size valves, if it were totally used by the super austenitic stainlesssteel, it will certainly cause a great waste, This paper is mainly on the existing low carbonsteel valves of big size, by Surfacing the austenite stainless steel welding rod on its innerface to prolong the lifespan of it. This paper through comparative analysis of the surfacinglayers of the welding rod A022、A102、A137、A302、A312、A402、homemade addingSi element rod as well as the Q235.The result of the polarization curve experiment show that in the4mol/L H2SO4solution and in the4mol/L H3PO4solution, the base material Q235has the worst Acidcorrosion resistance ability. The surfacing layer of the A402welding rod has the best Acidcorrosion resistance ability. In the4mol/L HNO3solution, the base material Q235has theworst Acid corrosion resistance ability. The homemade welding rod has the best Acidcorrosion resistance ability. The Salt spray corrosion experiment show that the basematerial Q235has the worst Cl-corrosion resistance ability. Surfacing layer of the A402welding rod has the best Cl-corrosion resistance ability. Friction and wear experimentshow that surfacing layer of the A402welding rod has the most excellent wear resistingproperty. the homemade welding rod has the worst wear resisting property. This paper also made a simple simulation of welding process in the two different kind current and volatgeparameters.