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Ferritic stainless steel

A stainless steel and ferrite technology, applied in furnace types, furnaces, heat treatment equipment, etc., can solve the problems of low fatigue characteristics, low thermal fatigue characteristics, high cost, large thermal expansion, etc., and achieve good corrosion resistance and good brazing properties. Effect

Active Publication Date: 2020-09-29
JFE STEEL CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, austenitic stainless steel contains a large amount of Ni, so there is a problem of high cost, and due to large thermal expansion, fatigue characteristics in use environments that are subject to high temperature and strong vibration such as components around the exhaust manifold, There is a problem with low thermal fatigue properties at high temperatures

Method used

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  • Ferritic stainless steel
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Experimental program
Comparison scheme
Effect test

Embodiment

[0118] Steel having the composition shown in Table 1 was melted in a vacuum melting furnace, heated at 1100 to 1200° C. for 1 hour, and then hot-rolled to produce a hot-rolled sheet having a thickness of 4.0 mm. After the hot-rolled sheet is annealed at 950-1100°C, the scale is removed, and the sheet is cold-rolled to a sheet thickness of 1.0mm. The surface of the cold-rolled annealed sheet obtained by finish-rolling and annealing at 950-1100 degreeC was polished to 600 grit with emery paper, degreased with acetone, and it was used for the test.

[0119] This cold-rolled annealed sheet was brazed with Ni-containing brazing filler metal as follows, and (1) evaluation of brazability was carried out, and (2) corrosion resistance was carried out on the cold-rolled annealed sheet after the brazing treatment. evaluation of.

[0120] (1) Evaluation of brazeability

[0121] Cut out a test piece with a width of 50 mm and a length of 50 mm from the cold-rolled annealed sheet, set a Ni...

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Abstract

Provided is a ferritic stainless steel having good corrosion resistance and exhibiting good brazeability when brazed with a Ni-containing brazing material at high temperature. This ferritic stainlesssteel has a composition containing, in mass%, 0.003-0.020% of C, 0.05-0.60% of Si, 0.05-0.30% of Mn, at most 0.040% of P, at most 0.020% of S, 17.0-22.0% of Cr, 0.20-0.80% of Ni, 0.30-0.80% of Cu, 0.01-0.10% of Mo, 0.001-0.015% of Al, 0.25-0.60% of Nb, and at most 0.020% of N, with the remainder comprising Fe and inevitable impurities, and satisfying equation (1) below. (1) 4Ni-(Si+Mn)>=0.00% (Inequation (1), Ni, Si, and Mn represent the contents (mass%) of the respective elements.)

Description

technical field [0001] The present invention relates to ferritic stainless steel, and in particular to ferritic stainless steel that exhibits good brazability when brazed at a high temperature using a Ni-containing brazing filler metal and is also excellent in corrosion resistance. Background technique [0002] In recent years, from the standpoint of protecting the global environment, further improvements in fuel consumption and enhancement of exhaust purification have been demanded for automobiles. Therefore, the application of exhaust gas recirculation devices such as heat recovery devices and EGR (Exhaust Gas Recirculation) coolers in automobiles is expanding. [0003] Here, the heat recovery device refers to a device that uses the heat of engine cooling water for heating, or uses the heat of exhaust gas to heat the engine cooling water to shorten the warm-up time when the engine is started, thereby improving fuel consumption. Usually, the heat recovery device is arrange...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/00C22C38/48C22C38/60C21D9/46
CPCC21D6/00C21D6/004C21D8/02C21D8/0205C21D8/0226C21D8/0236C21D9/46C22C38/00C22C38/001C22C38/002C22C38/004C22C38/005C22C38/008C22C38/02C22C38/04C22C38/06C22C38/42C22C38/44C22C38/46C22C38/48C22C38/50C22C38/52C22C38/54C22C38/60C21D6/005C21D6/007C21D6/008C21D8/0263C21D2211/005
Inventor 矢野孝宜市川真奈美中村彻之福田国夫石川伸杉原玲子山内克久松本英哉
Owner JFE STEEL CORP