Effect Of Rare Earth La On Corrosion Resistance And Mechanical Properties Of201Stainless Steel

The201stainless steel was Mn-Cr-N series austenitic stainless steel. They were low cost,easy to be processed, good toughness, strong of corrosion resistance, etc. They are widely usedin medical equipment, food processing, chemical production, petroleum refining, and otherfields. Due to a sustainable rise in the price of Nickel element and Nickel elements beingharmful to the human body, it is found that austenitic stainless steel including low Nickel is paidmore attention by people.Nickel element can expand the austenitic phase region and improve the corrosion resistanceof stainless steel. So reducing the content of Nickel element would affect the oneness ofaustenitic stainless steel organization and corrosion resistance. Increasing the content ofManganese and Nitrogen can expand the phase field of the201stainless steel and get a singleaustenitic organization. La element of Rare earth can improve the corrosion resistance ofstainless steel and the mechanics properties. Therefore, the researching of rare earth La on therole of new type of low Nickel austenitic stainless steel has important significance.In this study, different content of rare earth La element in the201stainless steel is the researchobject. We use vacuum melting furnace to smelt the201stainless steel and adopt the method ofthe second fabric to add rare earth element La to the201stainless steel. After forging, we usebox-type resistance furnace to deal with the201stainless steel. Through researchingorganizations, the morphology of precipitated phase, composition and distribution in the201stainless steel, we analyze the mechanism of rare earth element La in the201stainless steel.By analyzing experimental results, we draw the following conclusions. Rare earth element Lacan refine201stainless steel grains.It can also change the morphology of precipitated phase, composition and distribution. Whenthe content of rare earth element La is within the scope of0.0049%, with the increasing of thecontent of rare earth, the201stainless steel organization will be finer and uniform and themorphology of precipitation phase tend to be round, diffusing on the steel substrate. It’s components gradually changing sulfide Manganese into sulfide lanthanum. When the content ofrare earth element La is0.014%, precipitating phase gathered grow up and appear to be thezonal distribution.Adding rare earth element La into the201stainless steel can improve the electrode potentialof the matrix. It also can improve the corrosion resistance of the201stainless steel. In theprocess of simulating Marine atmospheric corrosion and seawater corrosion, when the contentof rare earth element La is within0.0049%, with the increasing of the content of rare earthelement La, the201stainless steel corrosion resistance increase gradually.When the rare earth element La is0.014%, its corrosion resistance is decreased obviously.Rare earth element La can improve the mechanical properties of the201stainless steel. Whenthe content of rare earth element La is within the scope of0.0049%, as the increasing of thecontent of rare earth element La, the201stainless steel gradually increase such as shockabsorption function, hardness value, yield strength, tensile strength and break elongation. Whenthe rare earth element La is0.014%, there is an obvious decline in the mechanical properties ofthe201stainless steel.