Heatproof stainless steel seamless tube and production method thereof

A technology of heat-resistant stainless steel and seamless pipes, applied in the field of metallurgy, can solve problems such as insufficient high-temperature strength, easy coarsening, poor tissue stability, etc., and achieve good mechanical properties

Active Publication Date: 2018-03-02
SHANXI TAIGANG STAINLESS STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the material lacks carbide-forming elements such as W and Mo, and the precipitation of M23C6 is insufficient, and it is easy to coarsen during the long-term aging process, resulting in insufficient high-temperature strength and poor structural stability.
[0007] Although the stainless steel disclosed in the above-mentioned patent documents has a certain heat resistance, its high-temperature strength and durability are obviously insufficient, and its structural stability is poor, so it cannot meet the requirements for the use of boiler tubes for superheaters and reheaters of 630-650°C ultra-supercritical power plant boilers.

Method used

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  • Heatproof stainless steel seamless tube and production method thereof
  • Heatproof stainless steel seamless tube and production method thereof
  • Heatproof stainless steel seamless tube and production method thereof

Examples

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preparation example Construction

[0044] In the second aspect, the present invention provides a method for preparing a heat-resistant stainless steel seamless pipe, comprising: making a billet from an ingot to form a billet; performing thermal processing on the billet to obtain a capillary; refining the capillary whole, followed by cold working to obtain a blank pipe; heating the blank pipe and keeping it warm.

[0045] Preferably, the ingot is produced by the following method: the alloy material or steel scrap is melted in an electric furnace, and after decarburization in the AOD furnace and refining in the LF furnace, the molten steel can be tapped when the weight percentage of the molten steel reaches the following ratio: C0.05%~0.12 %, Si≤0.3%, Mn 0.2%~2%, P≤0.03%, S≤0.02%, Cr 17%~23%, Ni 13%~19%, Cu 1.5%~4%, W0.1%~ 3%, Nb 0.1%-0.9%, N 0.1%-0.5%, B 0.003%-0.006%, RE 0.001%-0.2%; then the molten steel is cast into an ingot.

[0046] Preferably, before the ingot is billeted to form a tube billet, the ingot ...

Embodiment 1

[0076] The composition of the stainless steel seamless pipe of Example 1 is shown in Table 1.

[0077] The preparation method of the stainless steel seamless pipe of embodiment 1 is:

[0078] The alloy material is melted in an electric furnace, and after AOD decarburization and LF refining, the ingot is cast by die casting. The red is sent to the soaking furnace for heating at 1120°C, the holding time is 1.2min / mm; the heating is at 100°C / h to 1200°C and the holding time is 1.0min / mm. The blank is opened by radial forging, the opening temperature is 1150°C, the final forging temperature is 950°C, the total deformation of forging is 75%, and the tube blank is manufactured.

[0079] Drill a 40mm centering hole in the center of the tube billet, preheat the ring furnace to 950°C, and heat it for 1.2min / mm, and heat it to 1150°C through an induction furnace when it comes out of the furnace. Glass powder, use a vertical punching machine to expand the hole, and the tube blank after...

Embodiment 2

[0081] The composition of the stainless steel seamless pipe of Example 2 is shown in Table 1.

[0082] The preparation method of the stainless steel seamless pipe of embodiment 2 is:

[0083] The alloy material is melted in an electric furnace, and after AOD decarburization+ and LF refining, the ingot is cast by continuous casting. The red is sent to a soaking furnace for heating at 1130°C, and the holding time is 1.1min / mm; it is heated at 110°C / h to 1200°C and held at 1.0min / mm. The billet is opened by hot rolling, the rolling temperature is 1120°C, the final rolling temperature is 920°C, and the total rolling deformation is 65%, and it is manufactured into a tube billet.

[0084] Directly heat the solid tube billet to 1120°C in an inclined bottom furnace, the heating time is 2.0min / mm, and use a bacteria-type piercer to perforate after being released from the furnace. The surface temperature before piercing is 1080°C, and the top is coated with glass powder for lubrication...

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Abstract

The invention provides a heatproof stainless steel seamless tube. The heatproof stainless steel seamless tube comprises, by weight, 0.05-0.12% of C, 0.3% or less of Si, 0.2-2% of Mn, 0.03% or less ofP, 0.02% or less of S, 17-23% of Cr, 13-19% of Ni, 1.5-4% of Cu, 0.1-3% of W, 0.1-0.9% of Nb, 0.1-0.5% of N, 0.003-0.006% of B, 0.001-0.2% of RE, and the balance of Fe and inevitable impurities. The invention also provides a production method of the heatproof stainless steel seamless tube. The method comprises the following steps: cogging cast ingots in an open die forging, radial forging or rolling manner to produce a tube blank; carrying out hot working on the tube blank through a hot extrusion technology or a hot piercing technology to produce a tubular billet; finishing the tubular billet,and carrying out cold working in a multi-pass cold rolling or cold drawing manner to obtain a pierced billet; and heating the pierced billet, and performing heat preservation.

Description

technical field [0001] The invention belongs to the field of metallurgy. Specifically, the invention relates to a heat-resistant stainless steel seamless pipe and a preparation method thereof. Background technique [0002] Electricity is the foundation of industry. In recent years, my country's electric power industry has developed rapidly, and its total installed capacity has approached 1 billion kW, among which thermal power units are the absolute main force. The characteristics of my country's "rich coal, less oil and less gas" energy system determine the role of coal as an energy supply. Dominance, this situation is difficult to change for a long time. At present, China is facing enormous pressure to reduce emissions, and coal power generation will inevitably bring CO 2 , SO 2 , NO x A large amount of exhaust gas is discharged, causing serious environmental pollution. Therefore, effectively improving the thermal efficiency of coal-fired power generation units, increas...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/58C22C38/04C22C38/02C22C38/42C22C38/44C22C38/48C22C38/54C22C30/02C21D8/10B21C37/06
CPCB21C37/06C21D8/105C21D2211/001C22C30/02C22C38/001C22C38/005C22C38/02C22C38/04C22C38/42C22C38/44C22C38/48C22C38/54C22C38/58
Inventor 方旭东徐芳泓李阳夏焱王岩赵建伟王志斌
Owner SHANXI TAIGANG STAINLESS STEEL CO LTD
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