High-forming nitrogen-containing austenitic stainless steel and manufacturing method thereof

Abstract

The invention discloses a high-forming nitrogen-containing austenitic stainless steel and a manufacturing method thereof. The composition of the steel comprises the following components of, by weight,0.001-0.05% of C, 2.50-3.80% of Si, 6.0-8.0% of Mn, 13.5-15.0% of Cr, 1.0-2.5% of Ni, 0.12-0.15% of N, 3.5-5.0% of Cu, less than or equal to 0.004% of S, 0.1-0.2% of V, 0.1-0.2% of Nb, and the balance Fe and inevitable impurities, wherein C+N is less than or equal to 0.18% , (V + Nb) / C is larger than or equal to 5, the content of Si multiplied by 5.59 mJ / m<2> is greater than or equal to 14 mJ / m<2>, Md30 / 50 is 40-70 DEG C, the average grain size is larger than or equal to 90 microns, and the hardness is less than or equal to HV180. According to the preparation method disclosed by the invention, the Ni is replaced with nitrogen alloying, and the Mn, the Cu and the like which obtain austenite structures are added; the Si and the like are added, so that lower stacking fault energy is remarkably reduced; the initial hardness of a material is reduced, and the temperature of the MD30 / 50 is controlled, so that the martensite phase changes slowly in the strain process; the erishen value is larger than or equal to 14.5, LDR is larger than or equal to 2.4, the requirements of complex forming is met, and the performance is close to 304 DDQ with high forming and high cost, so that the steel can be widely applied to industries such as electronics, instruments and apparatus, products and the like.

Description

technical field [0001] The invention relates to austenitic stainless steel, in particular to a highly formed nitrogen-containing austenitic stainless steel and a manufacturing method thereof. Background technique [0002] Austenitic stainless steel 304 has good formability and is often used in deep drawing fields, such as stainless steel water cups and thermos bottles. In the field of deep drawing with particularly high requirements, such as water cups or sinks formed at one time, conventional 304 cannot meet the requirements when processing deep-drawn products, and cracks and pull-through phenomena are prone to occur, which affects the qualified rate of finished products. [0003] For this reason, a special deep-drawing material 304DDQ has been developed. Compared with ordinary 304, the nickel content of 304DDQ is increased from 8.0% to 8.5%, and about 3.5% of Cu is added. The austenite of the material has a more matching stability and the extension of the material The rat...

AI Technical Summary

Problems solved by technology

The above-mentioned patented material has high C and N content, and the initial strength of the material is high; although the material is in the austenite phase at room temperature, its austenite phase is metastable, and martensitic phase transformation occurs rapidly during forming

These all lead to the formability of nitrogen-containing nickel austenite lower than that of 304

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