Austenitic stainless steel and manufacturing method thereof

Abstract

The invention relates to low-nickel austenitic stainless steel with high polishing performance, which comprises the following chemical ingredients in percentage by weight: 0.05 to 0.12 percent of C, more than 0.3 percent and less than 1 percent of Si, 9.2 to 11.0 percent of Mn, 14.0 to 16.0 percent of Cr, less than or equal to 0.4 percent of Ni, 0.12 to 0.25 percent of N, less than 0.08 percent of P, less than 0.01 percent of S, 1.5 to 3.5 percent of Cu, more than or equal to 10*10<-4> and less than or equal to 30*10<-4> percent of B, more than or equal to 30*10<-4> and less than or equal to 60*10<-4> percent of Ca and the balance of Fe and inevitable impurities. A single austenite structure is obtained at room temperature by reasonable ingredient design on the premise of reducing the consumption of noble metal Ni substantially, so that the stainless steel has the high mechanical performance and a certain corrosion resistance. In addition, the purity of molten steel is improved by a scientific manufacturing method, and the defects of peeling, sand holes and the like of the stainless steel in the polishing process are overcome effectively by utilizing the technology of inclusion modification; and the grain size level of cold rolling products is controlled to avoid polishing stripes, so that the polishing performance is high. The low-nickel austenitic stainless steel can better meet the using requirement of the stainless steel with high polishing performance in fields of decoration, products and the like, and the cost is reduced greatly.

Description

technical field [0001] The invention relates to an austenitic stainless steel and a manufacturing method thereof, more specifically a low-nickel austenitic stainless steel with excellent polishing performance and a manufacturing method thereof. Background technique [0002] Austenitic stainless steels such as 304 and 316 are widely used in various fields of the national economy because of their excellent mechanical properties and corrosion resistance. However, the violent fluctuation of nickel price in recent years has brought huge risks to the production of austenitic stainless steel with high nickel content such as 304 and 316. The development of low-nickel or even nickel-free austenitic stainless steel has attracted people's attention. Low-nickel austenitic stainless steel has excellent mechanical properties and certain corrosion resistance, which can meet the requirements of use in weakly corrosive environments, such as decoration, products and other fields. However, st...

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Problems solved by technology

[0004] CN1584098A discloses a chemical composition of low-Ni austenitic stainless steel, although the alloying method of further reducing Ni content (Ni≤1.2%) and improving Mn content (8.5%≤Mn≤10.0%) is adopted in these chemical compositions , but did not consider adding a certain amount of Cu to improve the cold workability, and did not consider the technological measures to improve the polishing performance

However, the Ni content is still high, and the effect of Ca treatment to improve the purity of molten steel and the modification of inclusions to avoid peeling and trachoma during the polishing process and improve the polishability of stainless steel is not considered. At the same time, rare earth elements are difficult in industrial production. Joining and the yield rate is unstable, which is not conducive to the organization of industrialized mass production

[0007] CN1240839A has described the chemical composition of a kind of low Ni austenitic stainless steel, although also adopted to further reduce Ni content (1.0%≤Ni≤4.0%) in these chemical compositions, improve Mn content (5.0%≤Mn≤11.0%) The alloying method, and the addition of trace elements B and Ca is also considered, but the Ni content of this technology is still high and the technology does not add N elements, which reduces the austenite stability of the technology products, which is not conducive to cold forming

[0008] CN12160132A describes a chemical composition of low Ni austenitic stainless steel, in which the Ni content is reduced to a lower content (0.1%≤Ni≤2.0%), but the Mn content (5.0%≤Mn≤9.0%) Not very high, will reduce the stability of austenite

In addition, this technology does not take into account the process methods such as Ca treatment to improve the polishing performance of stainless steel.

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