Steel for nuclear-power containment with thickness of 6 mm and manufacturing method of steel

Abstract

The invention discloses steel for nuclear-power containment with thickness of 6 mm and a manufacturing method of the steel. The low-C and low-Mn composition series design for the steel, extra alloyingcomponents are not added, and an irradiation effect is taken into consideration while yield strength stability is guaranteed. According to the manufacturing method, by means of optimization of blanktype, length of a rolled piece is effectively controlled in a rolling process, and larger temperature fluctuation caused by the too long rolled piece is avoided. With the adoption of superhigh-temperature heating mechanism, higher temperature for blanks is obtained during rolling, and higher final rolling temperature for a steel plate is guaranteed after the rolling is finished. By means of control for the rolling process, temperature drop in the process is reduced, and smaller temperature difference fluctuation of the head and the tail of the rolled piece is guaranteed. The length of the rolled piece is optimized and an area with poorer plate cut is cut off, and performance uniformity of a sampling position is ensured. The 6mm nuclear-power steel produced with the method has the advantages that yield strength is controlled stably, the toughness matching is excellent, and requirements for performance are met completely. The performance qualification rate of production reaches 94%, andthe steel is completely applicable to industrial mass production.

Description

technical field [0001] The invention relates to a steel for nuclear power containment, in particular to a 6mm thick steel for nuclear power containment and a manufacturing method thereof. Background technique [0002] The reactor containment structure of a nuclear power plant is very important in the construction of a nuclear power plant, and it is called the last barrier of nuclear safety. The containment shell can be divided into three types according to the material: steel, reinforced concrete and prestressed concrete. The second-generation or second-generation improved nuclear power plants built in my country and the French-standard pressurized water reactor nuclear power plants mostly use reinforced concrete containment, that is, a reinforced concrete single-layer containment with a thin carbon steel lining. It consists of a shell and a hemispherical top. The representative steel types are mainly 20HR, P265GH, Q265HR, etc., and the strength level is the lower 265 level...

AI Technical Summary

Problems solved by technology

Since the upper and lower limits are less than 100MPa, the following problems often occur in the production process: 1. During the rolling process of thin gauge, the temperature drops rapidly, resulting in a large temperature difference between the head and tail of the rolled piece, and large performance fluctuations

2. In mass production, the requirement of yield strength ≥ 265MPa in the technical conditions can generally be met, but the average value is often less stable, and it is easy to exceed the upper limit, which leads to the change of the steel plate, resulting in an increase in production costs

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