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Ferritic stainless steel

A stainless steel and system technology, applied in the field of ferritic stainless steel, can solve the problem of high price, achieve low-cost manufacturing, good appearance, and the effect of preventing titanium veinlets

Active Publication Date: 2015-05-20
JFE STEEL CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this steel grade contains a large amount of Ni, so the price is high

Method used

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  • Ferritic stainless steel
  • Ferritic stainless steel
  • Ferritic stainless steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0067] The ferritic stainless steel having the composition of Invention Examples A1 to A5 and Comparative Examples C1 to C5 shown in Table 1 was smelted into a 30 kg steel ingot, heated to a temperature of 1150°C, and hot rolled to produce a plate thickness of 4.0 mm Hot rolled plate. Then, after annealing at 950° C. in an argon gas atmosphere, cold rolling was performed to produce a cold rolled sheet with a thickness of 0.8 mm. Next, annealing is performed at 930° C. in an argon gas atmosphere, and pickling is performed using a mixed acid of hydrofluoric acid and nitric acid.

[0068] For the inventive examples A1 to A5 and comparative examples C1 to C5 obtained above, the surface was polished with #600 sandpaper (polished to #600finish) to prepare test materials.

[0069] According to JIS H8502, the test material is subjected to salt spray cyclic corrosion test (salt spray cyclic corrosion test). The salt water spray cycle test is to spray 5% NaCl (35°C, 2hr) (spraying5%NaCl aq...

Embodiment 2

[0082] The ferritic stainless steel having the composition of Invention Examples B1 to B6 and Comparative Examples D1 to D4 (D4 is the ferritic stainless steel disclosed in Patent Document 1) shown in Table 2 was melted at 150 tonVOD, and then continuously cast It is cast as a steel billet. It was heated to a temperature of 1150°C and hot rolled to form a hot rolled steel ring with a thickness of 4.0 mm.

[0083] Next, after annealing in a combustion gas atmosphere of 950° C., acid washing was carried out with sulfuric acid, and then acid washing was carried out with a mixed acid of hydrofluoric acid and nitric acid to form a hot-rolled annealing and pickling steel ring. Then, the plate thickness is 0.8mm by cold rolling, and after annealing in a combustion gas atmosphere at 930°C, electrolytic discaling in neutral electrolyte (electrolytic discaling in neutral electrolyte) is performed, and then an acid using a mixed acid of hydrofluoric acid and nitric acid is performed. Wash ...

Embodiment 3

[0095] After the ferritic stainless steels having the compositions of invention examples E1 to E10 and G1 to G6 shown in Table 3 were melted at 150 ton VOD, they were cast into billets by continuous casting. In addition, the amount of B and Ca in E3 and E6, the amount of B in E9 and G4, and the amount of Ca in G6 are all unavoidable impurity levels. Each of the above-mentioned steel slabs was heated to a temperature of 1150°C and hot-rolled to produce a hot-rolled steel ring with a plate thickness of 4.0 mm. Next, after annealing in a combustion gas atmosphere at 950° C., pickling was performed using sulfuric acid, and then pickling was performed using a mixed acid of hydrofluoric acid and nitric acid to form a hot-rolled annealing pickled steel ring. Next, the plate thickness is 1.2mm by cold rolling, and after annealing in a combustion gas atmosphere at 930°C, neutral salt electrolysis is performed, and then pickling with a mixed acid of hydrofluoric acid and nitric acid is p...

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PUM

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Abstract

Provided is ferritic stainless steel which has excellent surface quality, while exhibiting excellent corrosion resistance and excellent acid pickling performance in a welded portion. Ferritic stainless steel which is characterized by containing, in mass%, 0.010% or less of C, 0.15-0.60% of Si, 0.5% or less of Mn, 0.04% or less of P, 0.01% or less of S, 0.2% or less of Al, 17.0-19.0% of Cr, 0.3-0.5% of Cu, 0.6% or less of Ni, 0.10-0.20% of Ti, and 0.015% or less of N, with C + N being 0.02% or less and with the balance made up of Fe and unavoidable impurities. The ferritic stainless steel is also characterized by satisfying formula (1). Ti% / (C% + N%) = 8 (1) In this connection, C%, N% and Ti% respectively represent the contents (mass%) of C, N and Ti.

Description

Technical field [0001] The present invention relates to ferritic stainless steel, and relates to a ferritic stainless steel having excellent quality of surface and excellent corrosion resistance and pickling properties of weld zone . Background technique [0002] Among stainless steels, austenitic stainless steel (austenitic stainless steel) SUS304 (18%Cr-8%Ni) (Japanese Industrial Standard, JIS G4305) is widely used due to its excellent corrosion resistance. However, this steel type contains a large amount of Ni and is therefore expensive. [0003] In contrast, Patent Document 1 discloses a ferritic stainless steel plate characterized by containing C: 0.03% or less, Si: 1.0% or less, Mn: 0.5% or less, P: 0.04% or less, as a component composition. S: 0.02% or less, Al: 0.1% or less, Cr: 20.5%~22.5%, Cu: 0.3%~0.8%, Ni: 1.0% or less, Ti: 4×(C%+N%)~0.35%, Nb : 0.01% or less, N: 0.03% or less, C+N: 0.05% or less, and the remainder is formed of Fe and inevitable impurities. This sta...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C38/00C22C38/50C22C38/54
CPCC22C38/001C21D6/002C22C38/002C22C38/004C22C38/02C22C38/04C22C38/06C22C38/42C22C38/50C22C38/54
Inventor 石井和秀山内克久石桥源一神丸秋信
Owner JFE STEEL CORP