A superalloy cast pipe material for a 700°C ultra-supercritical thermal power unit reheater and its preparation method

An ultra-supercritical, thermal power unit technology, which is applied in the field of materials and material preparation, can solve the problems of reducing service life and increasing brittleness of alloys, and achieves the effects of reducing processing costs, reducing the tendency of increasing brittleness, and improving high-temperature mechanical properties.

Active Publication Date: 2016-03-23
XIAN THERMAL POWER RES INST CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] However, during high temperature service of 20Cr32Ni1Nb alloy, the NbC inside the structure is unstable, and will migrate to the G phase (Ni 16 Nb 6 Si 7 ) or η’ phase (Nb 3 Ni 2 Si) transformation, resulting in increased brittleness of the alloy and significantly reducing its service life

Method used

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  • A superalloy cast pipe material for a 700°C ultra-supercritical thermal power unit reheater and its preparation method
  • A superalloy cast pipe material for a 700°C ultra-supercritical thermal power unit reheater and its preparation method
  • A superalloy cast pipe material for a 700°C ultra-supercritical thermal power unit reheater and its preparation method

Examples

Experimental program
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Effect test

Embodiment 1

[0043] The superalloy cast pipe material in this embodiment includes, by mass percentage: C: 0.1%, Cr: 22%, Mo: 0.5%, W: 2.5%, Nb: 1.0%, Mn: 0.5%, Si: 0.2%, Ni: 32%, the balance being Fe.

[0044] The preparation method of the present embodiment comprises the following steps:

[0045] 1) Raw material preparation: The ingredients include by mass percentage: C: 0.1%, Cr: 22%, Mo: 0.5%, W: 2.5%, Nb: 1.0%, Mn: 0.5%, Si: 0.2%, Ni: 32% , the balance is Fe;

[0046] 2) Melting: The alloy prepared in step 1) is smelted into an alloy mother liquor by using an intermediate frequency vacuum induction arc furnace, and the mass percentage content of P and S impurity elements in the mother liquor is controlled to be less than 0.03%. Finally, the alloy mother liquor is released when the temperature of the alloy mother liquor reaches 1650°C ;

[0047] 3) Casting: Pour the alloy mother liquor in step 2) into the centrifugal casting machine to fill and solidify to form a pipe, and use the ce...

Embodiment 2

[0054] The high-temperature alloy cast pipe material in this embodiment includes, by mass percentage, C: 0.2%, Cr: 24%, Mo: 0.5%, W: 2.0%, Nb: 1.0%, Mn: 0.5%, Si: 0.2% , Ni: 37%, the balance is Fe.

[0055] The preparation method of the present embodiment comprises the following steps:

[0056] 1) Raw material preparation: The ingredients include by mass percentage: C: 0.2%, Cr: 24%, Mo: 0.5%, W: 2.0%, Nb: 1.0%, Mn: 0.5%, Si: 0.2%, Ni: 37% , P: 0.03%, the balance is Fe;

[0057] 2) Melting: The alloy prepared in step 1) is smelted into an alloy mother liquor by using an intermediate frequency vacuum induction arc furnace, and the mass percentage content of P and S impurity elements in the mother liquor is controlled to be less than 0.03%. Finally, the alloy mother liquor is released when the temperature of the alloy mother liquor reaches 1650°C ;

[0058] 3) Casting: Pour the alloy mother liquor in step 2) into the centrifugal casting machine for filling and solidification,...

Embodiment 3

[0065] The superalloy cast pipe material in this embodiment includes, by mass percentage, C: 0.15%, Cr: 20%, Ni: 39%, Mn: 0.4%, Si: 0.2%, Nb: 1.6%, Mo: 2.0% , W: 1.0%, Ti: 0.3%, Al: 1.0%, N: 0.05%, B: 0.005%, Re: 0.1%, and the balance is Fe.

[0066] The preparation method of the present embodiment comprises the following steps:

[0067] 1) Raw material preparation: The ingredients include by mass percentage: C: 0.15%, Cr: 20%, Ni: 39%, Mn: 0.4%, Si: 0.2%, Nb: 1.6%, Mo: 2.0%, W: 1.0% , Ti: 0.3%, Al: 1.0%, N: 0.05%, B: 0.005%, Re: 0.1%, and the balance is Fe;

[0068] 2) Melting: The alloy prepared in step 1) is smelted into an alloy mother liquor by using an intermediate frequency vacuum induction arc furnace, and the mass percentage content of P and S impurity elements in the mother liquor is controlled to be less than 0.03%. Finally, the alloy mother liquor is released when the temperature of the alloy mother liquor reaches 1650°C ;

[0069] 3) Casting: Pour the alloy mot...

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Abstract

The invention belongs to the field of materials, and in particular relates to a high-temperature alloy cast tube for a 700 DEG C level ultra-supercritical thermal power generating unit reheater and a preparation method of the high-temperature alloy cast tube, aiming to obtain good high-temperature mechanical properties and simplify a processing technology. The adopted technical scheme is as follows: the high-temperature alloy cast tube comprises the following components in percentage by mass: 0.05-0.21% of C, 20-25% of Cr, 30-39% of Ni, less than or equal to 0.7% of Mn, less than or equal to 0.3% of Si, less than or equal to 1.6% of Nb, less than or equal to 2.5% of Mo, 1.0-3.5% of W, less than or equal to 0.3% of Ti, less than or equal to 1.0% of Al, less than or equal to 0.10% of N, less than or equal to 0.005% of B, less than or equal to 0.15% of Re and the balance of Fe. The preparation method comprises the steps of preparing raw materials, smelting, casting, and performing surface treatment and heat treatment. The alloy material disclosed by the invention reduces the brittleness increasing tendency of alloy during the service time, and the high-temperature mechanical properties of the alloy are improved through solid solution strengthening.

Description

technical field [0001] The invention belongs to the field of materials and material preparation, and in particular relates to a high-temperature alloy cast pipe material for a reheater of a 700°C ultra-supercritical thermal power unit and a preparation method thereof. Background technique [0002] As my country's electricity demand continues to increase, energy shortages and environmental pollution problems have become increasingly prominent, and the need to develop high-efficiency, energy-saving, and environmentally friendly power generation methods has become increasingly urgent. Thermal power generation has been the most important power generation technology in my country for a long time, and improving the steam parameters of the unit is considered to be the most effective way to solve the above problems. A lot of practice in the past has shown that the service performance of key component materials is the most important factor restricting the improvement of steam paramet...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C38/54C22C33/04
Inventor 严靖博谷月峰鲁金涛杨珍
Owner XIAN THERMAL POWER RES INST CO LTD
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