Heat-resistant high-niobium austenite steel and preparation method thereof

A technology of austenitic heat-resistant steel and content, applied in the field of high-temperature metal structural materials, can solve the problems of insufficient high-temperature strength, poor structural stability, affecting the safe operation of power stations, etc., to reduce grain boundary interface energy and improve grain boundary bonding. strength, the effect of improving the resistance to steam oxidation and flue gas corrosion

Active Publication Date: 2017-07-04
HUANENG POWER INT INC +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the HR3C alloy also showed some shortcomings during the service process, that is, the stability of the structure is poor, and the toughness of the alloy decreases rapidly with the increase of service time, which affects the safe operation of the power station.
At the same time, in the active 600°C ultra-supercritical units, the service temperature of HR3C is close to its limit. In the ultra-supercritical units exceeding 600°C (such as 650°C, 700°C), if the HR3C alloy is continued to be used as the final superheater and reheater The heater faces the problem of insufficient high temperature strength

Method used

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  • Heat-resistant high-niobium austenite steel and preparation method thereof
  • Heat-resistant high-niobium austenite steel and preparation method thereof

Examples

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Effect test

Embodiment 1

[0039] The tensile properties at room temperature of Example 1#-3# alloys are much higher than the HR3C index in the GB5310-2008 standard. As the temperature increases, the strength of austenitic heat-resistant steel will decrease. At 650°C and 700°C, the tensile strengths of the alloys of Examples 1#-3# are much higher than 374MPa of HR3C at 600°C. It is shown that the example alloys have excellent room temperature and high temperature strength.

[0040] The tensile properties of table 2 embodiment alloy and HR3C

[0041]

[0042] 5.2 Impact toughness

[0043] After the alloys of Examples 1#-3# were exposed to heat at 650°C for 500 hours, their impact toughness at room temperature is shown in Table 3, all of which are greater than 50J / cm 2 , higher than HR3C (45J / cm 2 ) above 10%. It shows that the alloy of the present invention has excellent impact toughness.

[0044] Table 3 Room temperature impact properties of the alloys of the examples and HR3C exposed to heat a...

Embodiment 4-7

[0048] Table 4 shows the chemical composition of Examples 4, 5, 6 and 7 of the present invention. Alloys 4#-6# used in the test are austenitic alloys with high niobium content in Examples 4, 5, 6 and 7 of the present invention.

[0049] The chemical composition (% by weight, balance is Fe) of the embodiment of the present invention 4-7 of table 4

[0050] alloy 4# 5# 6# 7# Ni 23 22 25 19 Cr 21 23 20 25 mn 0.5 0.3 1.0 0.8 Nb 2.5 3.5 4 2 Si 0.1 0.6 0.75 0.5 N 0.15 0.25 0.3 0.1 C 0.05 0.15 0.04 0.08 B 0.001 0.002 0.003 0.001 Zr 0.002 0.003 0.002 0.001 P 0.015 0.01 0.022 0.03 co 6.0 1.0 2.0 3.0 V 0.25 0 0.01 0.1 Ce <0.005

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Abstract

The invention relates to a heat-resistant high-niobium austenite steel and a preparation method thereof. The heat-resistant high-niobium austenite steel has the advantages of reasonable component design, excellent strength and toughness at a high temperature good processing performance and good cost performance. The heat-resistant high-niobium austenite steel comprises, by weight, 19-25% of Ni, 20-25% of Cr, 1.0-6.0% of Co, 1.0% or less of Mn, 2-4% of Nb, 0-0.5% of V, 1.0% or less of Si, 0.1-0.3% of N, 0.04-0.15% of C, 0.001-0.003% of B, 0.001-0.003% of Zr, 0-0.04% of Ce, 0.01-0.03% of P, and the balance of Fe. The preparation method comprises the following steps: casting alloy ingots; carrying out homogenization and thermal deformation treatment on the alloy ingots; and carrying out solid solution heat treatment on the heat-deformed alloy at 1180-1240 DEG C for 5-45 min, and carrying out water cooling to room temperature.

Description

technical field [0001] The invention relates to the technical field of high-temperature metal structural materials, in particular to an austenitic heat-resistant steel with high niobium content and a preparation method thereof. Background technique [0002] my country is rich in coal resources, and coal-fired thermal power units provide more than 75% of my country's electricity. This energy structure will be difficult to change for a long time in the future. At present, the average power generation efficiency of coal-fired thermal power units in my country is low, and energy consumption is high. x , carbon dioxide and mercury emissions, the pressure on environmental protection is high. Adopting high-parameter and large-capacity thermal power units is one of the most direct, economical and effective measures to achieve energy saving and emission reduction. Therefore, the development of high-parameter ultra-supercritical coal-fired power generation technology has very import...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/52C22C38/04C22C38/48C22C38/46C22C38/02C22C38/54C22C38/50C22C30/00C22C32/00C21D8/00
CPCC21D8/00C21D8/005C21D2211/001C22C30/00C22C32/0047C22C38/001C22C38/002C22C38/005C22C38/02C22C38/04C22C38/46C22C38/48C22C38/50C22C38/52C22C38/54
Inventor 袁勇朱传志尹宏飞党莹樱赵新宝严靖博杨珍鲁金涛周永莉黄锦阳
Owner HUANENG POWER INT INC
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