A691Gr2-1 / 4CrCL22 high temperature and high pressure steel pipe

First, SA691Gr2-1/4CrCL22 is mainly used as welded pipe for power equipment

A691 grade is mainly used for high temperature and high pressure carbon steel and alloy steel point melt welded steel nominal pipe

Second, SA691 is a high temperature and high pressure reconsideration condition with electric fusion welding steel and alloy steel standards, the grade of steel pipe reaches SA691Gr2-1/4Cr, to go through the effect force treatment, radiographic inspection and water pressure test. SA691Gr2-1/4CrCL22 is a kind of CR-MO heat-resistant steel, the basic components are 2.25% CR, 1% MO. Equivalent to the seamless tube SA-335P22, Maigang A691 is used as a welded pipe, and sa-335 P22 grade is American standard seamless pipe.

ASTM A691 is the standard of the American Society for Materials and Testing High temperature and high pressure service conditions with electric fusion welding carbon steel and alloy steel pipe standard. 1 1/4Cr is a steel pipe grade, specifically 1 1/4% chromium, 1/2% molybdenum steel grades. 22 is the heat treatment state

Fourth, A691 Gr2-1/4Cr CL22 and A691 Gr1-1/4Cr CL22 high temperature fusion alloy welded pipe nuclear power plant designated procurement, but the two materials are completely different, can not be substituted. Where is it from?

According to the results of the third national wind energy resource census, the land area of China’s technology-developable wind energy (wind energy power density of 150 watts / square meter and above) is about 200,000 square kilometers, and the total amount of wind energy on land and offshore is 700 million kilowatts to 1.2 billion kilowatts, and wind power will become an important part of the future energy structure. In the next 10 years, the period of rapid development of wind energy in China is expected to reach 150 million kilowatts by 2020.

6. On July 6, 2010, China’s first offshore wind farm – Shanghai Donghai Bridge adopted 34 sets of 3MW offshore wind turbines, with a total capacity of 100,000 kW offshore wind farm demonstration project grid-connected power generation, the pipeline used is A691 Gr2-1/4Cr CL22 welded pipe, wind power steel in coastal areas is required to have the performance of weathering steel, that is, it has the characteristics of high strength, air resistance and marine corrosion.

The core component of wind power, the head part, the material requirements for steel are higher, most of the head steel is special steel and non-modulated steel with a strength of more than 800 megapascals, etc., and some materials are stainless steel. (The design life of wind power generation equipment is 20 years) The nose is mainly composed of blades, gearboxes, generators, yaw systems, control systems and towers, among which the material of the wind turbine blades is glass fiber reinforced resin, carbon fiber, and the rest of the materials are steel.

7. Materials, sizes and quantities used in the four major pipelines of some 1000MW ultra-supercritical parameter units in China

Note: The inner diameter tube is (minimum inner diameter × minimum wall thickness); the outer diameter tube is (nominal outer diameter × nominal wall thickness)

8. The key parts of the ultra-supercritical unit are high temperature and high pressure steam pipes, headers, superheaters, reheaters and water-cooled wall pipes, etc., which all involve the problem of creep strength. Also, large components such as pipes and headers have to deal with fatigue problems due to thermal stress. Therefore, one of the keys to the promotion and application of ultra-supercritical technology is to develop and produce heat-resistant steel with better high-temperature performance that meets the requirements of regulations and ensures the safe and stable operation of the unit. Table 2 lists the four major pipeline materials of the unit.