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Heat-resistant austenitic stainless steel having excellent cyclic oxidation resistance

An austenitic and cyclic oxidation technology, which is applied in the field of heat-resistant austenitic stainless steel, can solve the problems of unconfirmed cyclic oxidation resistance, low cyclic oxidation resistance, and increased manufacturing procedures, and achieves suppression of oxide scale scattering. , The effect of improving power generation efficiency and reducing maintenance costs

Inactive Publication Date: 2014-01-15
KOBE STEEL LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, shot peening has other problems such as high cost due to increased manufacturing process, and improvement in cyclic oxidation resistance has not been confirmed, and it is expected that the cyclic oxidation resistance is low

Method used

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  • Heat-resistant austenitic stainless steel having excellent cyclic oxidation resistance
  • Heat-resistant austenitic stainless steel having excellent cyclic oxidation resistance
  • Heat-resistant austenitic stainless steel having excellent cyclic oxidation resistance

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0069] Melt various steel materials with the chemical composition shown in the following Table 1, and heat-forge a 20kg ingot melted in a vacuum melting furnace (VIF) into a size of width: 120mm×thickness: 20mm, after heat treatment at 1250°C , processed by cold rolling to thickness: 13mm. Thereafter, heat treatment was performed again at 1150° C. for 5 minutes, and this was used as a base material. A steel material of 20 mm x 30 mm x 2 mm was cut out from the base material by machining, and the surface of the steel material was smoothed / mirrored by grinding with sandpaper and buffing with diamond abrasive grains to prepare a test piece.

[0070] In addition, among the steel materials shown in the following Table 1, test Nos. 1 to 10 are steel materials (steels of the present invention) that satisfy the requirements specified in the present invention, and test Nos. 11 to 16 deviate from the requirements specified in the present invention. Among them, Test Nos. 14, 15, and 16 ...

Embodiment 2

[0081] For the invention steels of Test Nos. 1 to 6 shown in Tables 1 and 2, and the comparative steel of Test No. 14, the heat treatment temperature was changed in the temperature range of 1125 to 1275°C after cold working with a reduction in area of ​​35%. Samples with crystal grain sizes ranging from 4.5 to 10.0 were prepared from various steel materials. The cyclic oxidation test is to heat in the furnace for 25 minutes and let the air cool for 5 minutes. The sample is put in and out of the atmospheric furnace at 1100 ℃, and the mass of the test piece after 40 cycles is compared with the mass of the test piece in the initial state. Compare and obtain the mass reduction (loss: mg / cm －2 ).

[0082] Regarding the number of cycles, part of the steel to which Zr and Ce were added showed a significant improvement in loss, and the loss after 20 cycles had a degree of error depending on the particle size, so heating and cooling were repeated up to 40 cycles. In the calculation o...

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PUM

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Abstract

Provided is a heat-resistant austenitic stainless steel comprising: 0.05-0.2% C; 0.1-1% Si; 0.1-2.5% Mn; 1-4% Cu; 7-12% Ni; 16-20% Cr; 0.1-0.6% Nb; 0.05-0.4% Zr; 0.005-0.1% Ce; 0.1-0.6% Ti; 0.0005-0.005% B; 0.001%-0.15% N; 0.005% or less (excluding 0%) S; and 0.05% or less (excluding 0%) P, wherein the rest consists of iron and unavoidable impurities.

Description

technical field [0001] The present invention relates to a heat-resistant austenitic stainless steel suitable for use as a heat transfer tube material of a boiler, and in particular to a heat-resistant austenitic stainless steel excellent in resistance to cyclic oxidation. Background technique [0002] In recent years, in order to suppress the emission of carbon dioxide, which is a greenhouse gas, high efficiency of thermal power generation using coal has been promoted. In order to improve the power generation efficiency, it is effective to increase the steam temperature and pressure of the boiler, and as the heat transfer tube material of such a boiler, one having excellent high-temperature strength and oxidation resistance is suitable. In addition, as a material having such excellent performance, austenitic stainless steel is generally used. [0003] The oxidation resistance required as a heat transfer tube material is the resistance to cyclic oxidation. Since the boiler ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/00C22C38/58
CPCC21D6/004C22C38/001C22C38/002C22C38/005C22C38/02C22C38/04C22C38/42C22C38/44C22C38/48C22C38/50C22C38/54C22C38/58
Inventor 宫村刚夫难波茂信古屋和基
Owner KOBE STEEL LTD
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