Q345b Steel Plate

The continuous advancement of Q345b steel plate technology in smelting and heat treatment, and the development and production of forged (cast) steel plate by rolling has achieved fruitful results. The thickness of the steel plate that can replace forging (casting) parts has reached 410mm, and the maximum unit weight is 38 tons. Take the lead in transforming and perfecting large ingot production equipment in China, filling the gap of high-end products in the domestic wide and heavy plate field and replacing imports.

Large-thickness Z35-grade steel plate, taking advantage of technology and equipment, is a large-thickness Z-direction steel plate with a thickness of 200mm-300mm. The large-thickness Z35 steel plate is a kind of extra-thick steel plate used under specific environmental conditions, such as the turbine seat ring, guide vane and other key parts of the generator set, and its safety, reliability and longevity of service life are very high.

To develop a 200mm-300mm thick steel plate with a large thickness of Z35 grade, it is necessary to ensure that the anti-lamellar tearing performance reaches the Z35 grade. This is a highly difficult "Olympic competition question" recognized by the metallurgical industry. It is necessary to overcome technical difficulties such as solidification control of large steel ingots, heat treatment of large thickness steel plates, low temperature impact toughness of large thickness steel plates and laminar tear resistance.

Principles: One is to ensure that it has good weldability; the other is to ensure the performance in the thickness direction; the third is to ensure that it has sufficient impact toughness reserves and a low ductile brittle transition temperature at the use temperature; the fourth is to improve the safety of the structure.

Use fine craftsmanship to develop high-quality Z-direction steel products with large thickness for hydropower. For all process links such as smelting, rolling, heat treatment, the whole process is tracked, and the high temperature radiation of 500 degrees Celsius is tolerated, and the 200mm thick S355J0-Z35 and 270mm thick A516Gr70-Z35 steel plates have been developed successively based on EN10025 standards and hydropower design. According to the technical requirements of the institute, the Z35 steel plate with a thickness of 300mm was finally successfully developed. After inspection, it can fully meet the requirements of relevant technical standards and reach the actual level.

Its successful development has greatly advanced the development level of my country's hydropower large-thickness Z-steel technology. The successful research and development of 300mm thick Z35 steel plate has changed the situation that my country's hydropower industry has long relied on imports of large-thickness Z-direction steel, which is vital to the localization of large-scale equipment.

The 300mm-thick Z35 steel plate is a new node for the large-thickness Z-direction steel to enter the hydropower industry. This will inevitably promote continuous breakthroughs in the development of large-thickness Z-direction steel for hydropower. More importantly, the 300mm thick Z35 steel plate can be used not only in the hydropower industry, but also in the manufacture of other large-scale key equipment, which has broad prospects.