High-corrosion resistance high-toughness high-chromium ferrite stainless steel plate and manufacturing method thereof

Abstract

The invention discloses a high-corrosion resistance high-toughness high-chromium ferrite stainless steel plate and a manufacturing method thereof. The high-corrosion resistance high-toughness high-chromium ferrite stainless steel plate comprises, by weight, 0.005 to 0.015% of C, 0.005 to 0.020% of N, 0.2 to 0.5% of Si, 0.2 to 0.5% of Mn, less than or equal to 0.035% of P, less than or equal to 0.010% of S, 25 to 28% of Cr, less than or equal to 4.0% of Ni, 2.0 to 4.0% of Mo, 0.1 to 0.3% of V, 0.10 to 0.30% of Ti, 0.2 to 0.4% of Nb, less than or equal to 0.005% of Al, less than or equal to 0.005% of O, and the balance Fe and unavoidable impurities, wherein based on Cr content, Mo content, Ti content, Nb content, C content and N content respectively represented by Cr, Mo, Ti, Nb, C and N, Cr+3.3*Mo is greater than or equal to 35% and Ti+Nb is greater than or equal to 16(C+N). The high-corrosion resistance high-toughness high-chromium ferrite stainless steel plate has a ductile-brittle transition temperature below -40 DEG C, pitting potential above 1000mv, a critical pitting temperature above 70 DEG C, a corrosion rate below 0.2g / m<2>h in boiling hydrochloric acid having a concentration of 1wt%, yield strength above 380MPa, tensile strength above 520MPa, an elongation rate A50mm above 25% and Vickers hardness of 180 to 220, and can be used in various harsh environments.

Description

technical field

[0001] The invention relates to a high-corrosion-resistant, high-toughness, high-chromium ferritic stainless steel plate and a manufacturing method thereof. The ductile-brittle transition temperature of the steel is below -40°C, the pitting potential is above 1000mv, and the critical pitting temperature is 70°C Above, the corrosion rate is 0.2g / m in boiling hydrochloric acid with a concentration of 1% by mass 2 h or less, the yield strength is above 380MPa, the tensile strength is above 520MPa, the elongation A50mm is above 25%, and the Vickers hardness is 180-220. Background technique

[0002] Ferritic stainless steel is a stainless steel with a chromium content of 11-30%, a body-centered cubic crystal structure, and a ferrite structure in use. In addition to general corrosion resistance, ferritic stainless steel also has good local corrosion resistance such as chloride pitting corrosion, stress corrosion and crevice corrosion. In addition, ferritic stainl...

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