On October 1, workers at the Hanbao Hot Rolling Plant of Hegang Group Handan Steel Company were carefully inspecting the quality of corrosion-resistant steel to provide high-quality prepared material for the next process.

On October 1, at the pickling and rolling production line of the Hanbao Cold Rolling Plant of Hegang Group Handan Steel Company, the units were roaring, and matte light-gray steel strips were moving at a constant speed between the units, advancing steadily toward the next process after pickling and rolling. During the National Day holiday, Liu Hongyan, a special-grade technical supervisor at the Handan Steel Technology Center, and her colleagues remained at the production front line, following the entire production process of 09CrCuSb-BDL cold-rolled-continuously annealed sulfuric acid dew point corrosion-resistant structural steel. "This is the first time Handan Steel has produced 09CrCuSb-BDL cold-rolled-continuously annealed sulfuric acid dew point corrosion-resistant structural steel, and the customer requires a width of 2,040 millimeters and a thickness of 2 millimeters, which belongs to 'dual-limit' specifications and is very difficult to produce." Starting at 8 a.m., Liu Hongyan, wearing a safety helmet and blue work clothes, kept moving between the rolling mill stands, the on-site sampling points, and the main control room. Bending down to observe the surface condition of the high-speed steel strip, then returning to the main control room to stare at the constantly changing rolling and annealing parameters on the operation screen, she filled her notebook with dense notes on composition verification and shape control adjustment points.

This new product is a customized achievement of Handan Steel's collaborative research with downstream customers on production-demand coordination, specially serving the manufacture of thin-plate components for thermal power plant radiators, and focusing on solving the industry pain point of synergistic corrosion from high-temperature oxidation and sulfuric acid media under 150°C-550°C sulfur-containing flue gas conditions. "Enhancing the supply capacity of high-end steel and filling shortcomings in key materials is necessary for the development of the steel industry and also an important breakthrough for us to improve efficiency," Liu Hongyan said. This steel contains special alloy elements such as copper and antimony, and its process window is narrow. During cold rolling and annealing, it is highly prone to problems such as surface color differences and shape fluctuations, placing extremely high requirements on full-process control. "Keep a close watch on the rolling mill tension and strictly adhere to the thickness tolerance in the customized agreement. Surface quality directly determines the service life of downstream equipment," Liu Hongyan repeatedly stressed the key control points to the operators. Relying on the optimized design of a copper-chromium-antimony ternary corrosion-resistant synergistic system, this new product can form a dense and stable protective film in high-temperature sulfur-containing flue gas environments. Compared with ordinary carbon steel, its corrosion rate is greatly reduced, and it can replace some high-priced imported stainless steel. The product can not only help thermal power equipment extend maintenance cycles and reduce full-life-cycle operation and maintenance costs, but its ultra-thin specification plates can also help make radiators lighter and improve waste heat recovery and heat exchange efficiency, aligning with the development direction of energy conservation and carbon reduction in the industrial sector.

"After traditional hot-rolled sulfuric acid dew point corrosion-resistant structural steel is rerolled into thin plates, its corrosion resistance noticeably declines under high-temperature conditions of 150°C-550°C." Taking advantage of a brief gap in production, Liu Hongyan explained, "This time we did not simply copy the original grade, but started with composition ratios and matched them with collaborative optimization of the entire cold rolling-continuous annealing-tempering process, filling the industry gap in stable supply of thin-specification cold-rolled-continuously annealed sulfuric acid dew point corrosion-resistant structural steel and providing domestically produced material support for domestic thermal power waste heat recovery equipment. At the same time, this product is priced 300 yuan per ton higher than ordinary 09CrCuSb products, and the benefits are excellent!"