The Chinese Society for Metals held a scientific and technological achievement evaluation meeting on "development and application of low-energy-consumption smelting technology based on laterite nickel ore and resource-saving high-corrosion-resistant stainless steel products"
On February 15, 2022, the Chinese Society for Metals organized a video conference organized by Fujian Qingtuo Special Steel Technology Research Co., Ltd., Qingtuo Group Co., Ltd., Harbin Welding Research Institute Co., Ltd., Fujian Dingxin Industrial Co., Ltd., Fujian Qingtuo Tuo Nickel Industry Co., Ltd. and Fujian Dingxin Technology Co., Ltd. jointly researched and completed the achievement evaluation meeting of “low energy consumption smelting technology based on laterite nickel ore and development and application of resource-saving high corrosion-resistant stainless steel products”. The experts of the evaluation committee listened to the project technical report, novelty search report and application report, etc. After inquiries and discussions, they believed that the achievement has reached the international leading level.
The project results use laterite nickel ore as raw material. In view of the problems of high energy consumption, high cost, lack of nickel resources and high alloy cost in the existing smelting process of chromium-nickel stainless steel, a low-energy consumption smelting technology and resource-saving type based on laterite nickel ore are developed. Research on the development and application technology of high corrosion-resistant stainless steel varieties. The achievement has been granted 15 authorized patents (including 10 invention patents), 8 software copyrights, and 18 standards (including 2 Chinese standards, 2 industrial standards, and 14 group standards). Countries along the “Belt and Road” have significant economic and social benefits. The main innovations are as follows:
1. Pioneered the new process of smelting stainless steel by RKEF and AOD furnaces, and built the world’s first production line of laterite nickel ore RKEF smelting nickel molten iron directly sent to AOD furnace to smelt stainless steel, and realized 100% hot nickel molten iron and stainless steel smelting. The service life of the submerged arc furnace reaches more than 9 years, the electricity-saving per ton of steel is 580kWh, the cost is reduced by more than 330 yuan, and the comprehensive steelmaking cost is reduced by more than 0%.
2. Developed a nitrogen-alloyed nickel-saving austenitic stainless steel with excellent pitting corrosion resistance and sulfuric acid corrosion resistance and its manufacturing process. The world’s first resource-saving high-corrosion-resistant QN1803 stainless steel has formed QN series austenitic stainless steel products (pitting corrosion The equivalent PREN value is 18.5~32.0), compared with 304, 304L, 316L and 317L, and other chromium-nickel stainless steels, the yield strength is increased by more than 30%, the nickel content is reduced by 26~63%, the molybdenum content is reduced by more than 50%, and the alloy cost is reduced by 20%. % or more, the comprehensive use cost is reduced by more than 30%.
3. Developed a series of welding materials such as QN series nitrogen-alloyed nickel-type austenitic stainless steel supporting welding rods, welding wires, flux-cored welding wires, etc., which solved the loss of nitrogen element in the weld, pores, hot cracks and pitting caused by the heat-affected zone. The technical problems such as the reduction of impact toughness and impact toughness have formed the welding process specification and realized the engineering application.