Ferritic cr-containing steel

A ferrite and steel technology, applied in the direction of furnace type, furnace, heat treatment equipment, etc., can solve the problems of reduced processability, high temperature fatigue, etc., and achieve the effect of improving life and reducing thermal strain

Inactive Publication Date: 2007-01-24
JFE STEEL CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, it is pointed out that high strength based on high alloying inevitably leads to the problem of lower workability, and i

Method used

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  • Ferritic cr-containing steel
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  • Ferritic cr-containing steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0065] 50 kg of steel ingots (invention example, comparative steel, and conventional steel (Type429Nb, SUH409L)) having the composition shown in Table 1 were prepared, heated to 1100° C., and hot-rolled into 4 mm-thick hot-rolled sheets. Then, relative to these hot-rolled sheets, annealing of hot-rolled sheets (annealing temperature: 1090° C.)-pickling-cold rolling (cold rolling ratio: 62.5%)-final annealing (as shown in Table 1, annealing temperature Change from 900°C to 1220°C, hold at each temperature for 3 minutes, air-cool, adjust the amount of precipitated W)-acid pickling, and make a 1.5mm steel plate.

[0066] The coefficient of thermal expansion of the thus obtained cold-rolled and annealed sheets was investigated. The results are recorded in Table 1 together.

[0067] The average coefficient of thermal expansion at 20°C to 800°C was measured and evaluated as follows.

[0068] Using the vertical thermal dilatometer DL-7000 type produced by Vacuum Technology Co., Ltd...

Embodiment 2

[0081] Next, the relationship between the amount of precipitated W and the annealing temperature of the hot-rolled sheet was investigated. A 50kg steel ingot consisting of 0.005%C, 0.07%Si, 1.02%Mn, 15.2%Cr, 1.92%Mo, 3.02%W, 0.51%Nb, and 0.004%N was produced, and the steel ingot was heated to 1100°C Afterwards, it is made into a 4 mm thick hot-rolled plate by hot rolling. Next, for the hot-rolled sheet, annealing of the hot-rolled sheet (annealing temperature: change from 900°C to 1200°C, hold at each temperature for 3 minutes, then perform air cooling)-pickling-cold rolling (cold rolling) rate: 62.5%)-finish annealing (holding at the final annealing temperature of 1100° C. for 3 minutes, followed by air cooling)-acid pickling to produce a 1.5 mm annealed steel sheet.

[0082] The amount of precipitated W in the thus obtained cold-rolled annealed steel sheet was measured by the same method as in Example 1. In addition, on each steel sheet, samples for evaluating the amount o...

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Abstract

Disclosed is a ferritic Cr-containing steel whose thermal expansion coefficient is decreased for advantageously solving problems related to thermal expansion/contraction. Specifically disclosed is a ferritic Cr-containing steel consisting of, in mass%, C: 0.03% or less, Mn: 5.0% or less, Cr: 6-40%, N: 0.03% or less, Si: 5% or less, W:2.0-6.0% and the balance of Fe and unavoidable impurities, which is characterized in that the deposited W is not more than 0.1% and the average thermal expansion coefficient at 20-800 DEG C is less than 12.6 x 10<-6>/ DEG C.

Description

technical field [0001] The present invention relates to a ferritic Cr-containing steel material with low thermal expansion coefficient (thermal expansion coefficient), in particular to automobile exhaust system components, such as exhaust manifolds, exhaust pipes, converters Shell materials, metal honeycomb materials or separators in solid oxide fuel cells, materials for internal connectors, reformers as peripheral parts of fuel cells ), materials for exhaust ducts of power generation plants, heat exchangers, etc. Ferrite with a low thermal expansion coefficient suitable for repeated heat cycles between high and low temperatures Cr-containing steel. Wherein, the thermal expansion coefficients referred to in the present invention all mean linear thermal expansion coefficients. Hereinafter, it is abbreviated as thermal expansion coefficient. Background technique [0002] Various components that repeat thermal cycles between high temperature and low temperature undergo repea...

Claims

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Application Information

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IPC IPC(8): C22C38/00C21D9/46C21D6/00C21D8/02C21D8/04
CPCC21D8/0426C22C38/26C21D8/0273C22C38/02C21D8/0226C22C38/04C21D2211/005C22C38/22C21D6/002C21D8/0473F28F21/083
Inventor 宫崎淳加藤康古君修
Owner JFE STEEL CORP
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