Recently, 1,800 tons of high-strength ship plates (DH690 quenched and tempered ship plate steel for welded structures) were sent to Guangdong from Zhongnan Steel Echeng Steel and used to construct national large-scale LNG-powered ships. It has a positive effect on the localization of the use of high-end ship steel. This move also indicates that Egang has significantly improved ship plate strength from 355MPa to 690MPa.

DH690 quenched & tempered ship plate steel for welded structures has the advantages of high strength, small cutting deformation, easy welding, and stable low-temperature performance. It can be used in large marine parts, hull structures, deck machinery and equipment, port machinery, offshore oil production platforms, offshore construction, and various types of ocean engineering. It can meet steel's special technical performance requirements for LNG-powered ships, cruise ships, etc.

During the development process, with the technical support of Baowu Central Research Institute, the value creation team of Egang's wide and thick plate products overcame technical difficulties one after another. To achieve excellent performance results, the R&D team adopted a low-carbon and multi-alloy composite composition design and optimized temperature and shape control technology to obtain a good steel plate rolling shape. During the quenching heat treatment process, the team carefully adjusted the water cooling parameters to achieve a breakthrough in shape control of the 8mm thick ultra-high-strength sheet. They conducted multiple batches of tempering tests in the laboratory, so they obtained first-hand information on the optimal tempering process parameters, which were then verified in industrial furnaces and finally achieved good flatness and excellent comprehensive properties of DH690 steel plates. Mechanical properties meet the standard requirements of classification society regulations.

The successful development and supply of the product expanded the order thickness of E-steel's ultra-high-strength ship plates from 10mm to 8mm. It filled the gap in quenched and tempered ship-plate steel for Zhongnan Iron and Steel's 690MPa grade welded structures, becoming E-steel's wide plate. Product market development provides new growth points.