Steel for hydraulic power

1. The steel used in hydropower stations mainly includes the following four types:

1. Infrastructure steel It is mainly used for engineering construction such as foundations and dam areas. It requires ordinary threaded steel, wire rods, and steel sections. It is generally purchased and constructed by engineering units. It belongs to general steel products and is not within the scope of variety steel. The amount is related to the installed capacity of the hydropower station, the location and structure of the dam, etc.

2. Metal structure steel The manufacture of metal gates, hoists and closing machines, and inner walls of pipe wells in the dam area requires low-alloy medium and thick plate products such as 0345 and Q345R. It may be purchased by the construction party or the owner unit. It belongs to general steel products.

3. Pressure pipe steel The hydropower steel we generally refer to refers specifically to this type of product, most of which are wide and thick plates. It is used for the manufacture of water diversion pressure pipes in the plant dam, as well as auxiliary facilities such as ribs, bifurcated pipes, and volutes. There are relatively strict requirements on the chemical composition, tensile strength, (low temperature) impact energy and other properties of the steel plate. This part of the product is generally purchased by the owner unit through bidding, and arrives at the construction site in batches. The construction unit is responsible for rolling, welding, installation and other work. On the one hand, it can reduce the impact of material price fluctuations, and most importantly, it can ensure that the quality of the product can meet the design and use requirements of the hydropower station.

4. Turbine steel It is mainly used for the manufacture of turbine blades, and generally uses hot-rolled yoke steel plates.

2. Performance and use of hydropower special steel (pressure pipe) Hydropower special steel belongs to pressure vessel steel plates, which are generally medium and thick plate products. In the early hydropower station construction, 500MPa grade steel plates were generally used, mainly domestic 16MnR and American standard ATSM A537CL1. The tensile strength of the steel plate is not less than 500MPa. With the increasing installed capacity and head of hydropower stations, higher requirements are put forward for steel plates-using steel plates with higher strength, better low-temperature toughness and better welding performance. At present, the pressure steel pipes of domestic hydropower stations mainly use 600MPa grade products. In addition, most pumped storage power stations have begun to use 800MPa grade hydropower steel to reduce the wall thickness of steel pipes, volutes, and branch pipes and reduce the difficulty of construction and welding because of the high HD value. The following requirements are imposed on the performance of steel plates

1. The tensile strength is higher than 610MPa,

2. The performance of extra-thick steel plates is excellent, and the resistance to lamellar tearing is excellent;

3. The strength distribution of steel plates is concentrated, and the dispersion is small;

4. The steel plates have low welding crack sensitivity and reheating crack sensitivity, and good welding performance