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Chromium-nickel microalloyed carbon steel nuclear power seamless steel pipe and production method thereof

A technology of micro-alloying and seamless steel pipes, applied in the direction of improving process efficiency, can solve the problems of affecting the stability of the power grid, accelerated corrosion rate, accelerated corrosion rate, etc., to increase operational safety, prolong service life, and improve power generation. The effect of efficiency

Active Publication Date: 2016-06-01
TIANJIN STEEL PIPE MFG CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, ordinary carbon steel pipes have a high fluid-accelerated corrosion rate. In order to ensure the safety of nuclear power pipes, the steel pipes need to be inspected and replaced regularly, which increases the frequency of start-up and shutdown of nuclear power plants, reduces the operating efficiency of nuclear power plants, affects the stability of the power grid, and also increases The possibility of thermal fatigue failure of other steel pipes in nuclear power plants
Therefore, the high fluid-accelerated corrosion rate of carbon steel pipes not only affects the working efficiency of nuclear power plants, but also affects the safety of nuclear power plants.

Method used

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  • Chromium-nickel microalloyed carbon steel nuclear power seamless steel pipe and production method thereof
  • Chromium-nickel microalloyed carbon steel nuclear power seamless steel pipe and production method thereof
  • Chromium-nickel microalloyed carbon steel nuclear power seamless steel pipe and production method thereof

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] The chemical composition of the carbon steel nuclear power seamless steel pipe and the common carbon steel pipe of the chromium-nickel microalloying of the present invention is as follows:

[0021] Table 1 Tube blank chemical composition (wt%)

[0022]

[0023] In order to ensure the yield of nickel and the stability of the composition in the steelmaking process, the nickel plate is cut into an area less than 10cm 2 At the same time, the weight of the ferrochrome block is less than 10 kg / block; after the molten steel enters the VD, the high vacuum time is kept for not less than 10 minutes to ensure that the gas content of the steel is very small.

[0024] In addition, Ni and Cr in ordinary carbon steel pipes in Table 1 are residual elements in steel, not intentionally added elements. The five elements P, S, Mo, Cu, and Al are all residual elements, which should be limited according to the standard control amount.

Embodiment 2

[0026] The rolling requirement of steel pipe of the present invention is as follows:

[0027] The tube billet with large cross-section is used, rolled by the PQF high-precision three-roll continuous rolling mill, and then the tension is reduced. There are three deformations in total, and the deformation is large. The specific rolling is shown in the following table:

[0028] Table 2 Rolling specifications and deformation

[0029]

[0030] At the same time, in order to ensure the complete transformation of the structure, the subsequent heat treatment can only be carried out after the steel pipe is cooled to below 350 °C.

Embodiment 3

[0032] All steel pipes are normalized at 920°C. After normalizing, impact and fluid accelerated corrosion tests at -20°C are carried out. The results are as follows:

[0033] Table 3 Performance Test

[0034]

[0035] From the above test results, it can be seen that by improving the composition on the basis of ordinary carbon steel pipes, the impact energy of the steel pipes produced by the present invention at -20°C is increased by more than 250% compared with ordinary carbon steel pipes, and the fluid accelerated corrosion rate is reduced at the same time up to about 45%. ,

[0036] The results of the above tests of the steel pipes produced by the present invention all meet the requirements of nuclear power plants for the use of non-nuclear grade nuclear power pipes in conventional islands and nuclear islands, and can be processed and installed in cold weather in the north.

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Abstract

The invention provides a chromium-nickel microalloyed carbon steel nuclear seamless steel tube. The steel tube is prepared from the following components in percentage by weight: 0.16-0.20 percent of C, 0.17-0.25 percent of Si, 0.35-0.50 percent of Mn, 0.15-0.30 percent of Cr, 0.06-0.12 percent of Ni, and the balance of Fe, while the amount of P, S, Al, Mo and Cu serving as residual elements in steel is controlled according to standard. The invention further provides a method for producing the hot-rolled seamless steel tube. The steel tube has the effects that by means of microalloying, the flow accelerated corrosion resistance rate of the carbon steel tube can be reduced by about 45 percent, the transverse low-temperature average impact energy of steel at -20 DEG C is improved by about 250 percent and reaches about 80J on average, the service life of the steel tube can be prolonged, the changing frequency of the steel tube can be reduced, and the power generation efficiency of a nuclear power station can be improved. Therefore, brittle fracture of the steel tube due to cracking generated when the steel tube is processed at low temperature cannot happen, and the operation safety of the steel tube at low-temperature environment can be improved.

Description

technical field [0001] The invention relates to a chromium-nickel micro-alloyed carbon steel nuclear power seamless steel pipe for anti-fluid accelerated corrosion (FAC) and taking into account -20°C low-temperature impact toughness and its production method, which is mainly used in conventional islands and nuclear islands of nuclear power plants non-nuclear grade. Background technique [0002] As an indispensable energy source for people's daily life, electricity is also the blood of industrial development, so the demand is quite large. As a clean energy source, nuclear power can achieve zero emission of harmful gases, and because of its increasing safety, it has received strong support from the state. [0003] Non-nuclear-grade carbon steel pipes for conventional islands and nuclear islands, because they work in an environment where the medium is accelerated and the medium is supersaturated steam, it is necessary to prevent accelerated corrosion of the fluid. However, or...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C38/40C22C38/42C22C38/44C21D8/10
CPCY02P10/20
Inventor 肖功业何彪张俊萍赵庆权许磊磊
Owner TIANJIN STEEL PIPE MFG CO LTD