A few days ago, Shougang Jingtang's Composite Medium Plates were supplied to the Jiyang Yellow River Highway-Railway Grand Bridge Project generally contracted by the China Railway Construction Bridge Engineering Bureau. They will be used in the deck part of the bridge.

The Jiyang Yellow River Highway-Railway Grand Bridge is a control project of the Jinan-Binzhou High-Speed Railway, which is an important part of the intercity rail network for urban agglomeration in the Shandong Peninsula, one of the fast passages for the "One Ring Road and Six Radiating Expressways" in the economic circle of provincial capital urban agglomeration in Shandong Province, and one of the most important diverging collection and distribution passages of Jinan Yaoqiang International Airport.

Jingtang's Medium-Thick Plate Business Division, in conjunction with the Shougang Marketing Center and Jingtang's Manufacturing Department, Sales Department and other units, made plans well in advance, intervened in the planning and design of the bridge project in good time, and deeply connected with the customer, providing them with material solutions and winning their recognition. Focusing on the key project, the Medium-Thick Plate Business Division continuously carried out work related to the improvement of product quality and development and expansion of high-end products. For key projects, special personnel were arranged to track the whole process through contract bidding and production to delivery, forming a supply guarantee team to handle the whole process of technology, quality, production and sales in order to ensure product quality and meet the requirements of contractual delivery and use according to the high standards of the customer.

The thickness of the carbon steel and stainless steel composite plates rolled for this project was "3 + 16 mm". The "3 mm" refers to the thickness of the stainless steel, which accounts for a large proportion of the thickness of the composite plate and has high strength, so a rolling mill with higher power was needed to complete composite rolling to this thickness specification. Processes such as shape straightening treatment, surface treatment and tempering strengthening treatment are often required in rolling bonding. Edge defects can easily appear on composite plates produced via the TMCP process, and the deformation is large in pass rolling. In order to avoid rolling defects, there are strict control requirements for the welding quality of billets, rolling temperature and period, transfer time of billets and pass processing rate. If the control is insufficient, defects such as edge cracks, shape out of tolerance and size out of tolerance will occur, leading to the scrapping of billets. In order to reduce the degradation rate of trial products and improve the one-time yield, the production, marketing and research team of composite plates, in conjunction with the Manufacturing Department and Sales Department, worked together to overcome many unfavorable factors, sum up past production experience, carry out sufficient R&D experiments on stainless steel varieties with large thicknesses, fully consider the various problems that may occur in trial production, reduce the occurrence of strip products and contribute to the cost reduction and efficiency increase of the Medium-Thick Plate Business Division.

At present, the first batch of 333 tons of materials in this contract has entirely entered the preparation process for production, and the second batch of 1,553 tons of materials is being assembled. They will be delivered to customers and put into use as soon as possible. The successful R&D of carbon steel and stainless steel composite plates for bridges plays an important role in promoting the optimization of Jingtang's product structure, process technology level and brand effect.