Shanxi Taigang Stainless Steel Co., Ltd. Applies for Patent on High-Strength, High-Hardness Super Duplex Stainless Steel Coil and Its Production Method
On June 25, 2024, Shanxi Taigang Stainless Steel Co., Ltd. applied for a patent titled “A High-Strength, High-Hardness Super Duplex Stainless Steel Coil and Its Production Method,” with application publication number CN118241099A and an application date of March 21, 2024.
This invention discloses a high-strength, high-hardness super duplex stainless steel coil and its production method. The method includes preparing a hot-rolled coil of super duplex stainless steel, where the main chemical composition is controlled as follows: C 0.015-0.025%, Cr 25.0-25.5%, Ni 6.4-6.8%, Mo 3.0-3.5%, N 0.25-0.30%. The hot-rolled coil is then annealed at a temperature of 1050-1100°C, with annealing time based on the thickness of the coil, controlled at 0.5-2 min/mm. After annealing, the coil is cold-rolled with a deformation rate of 15-20%, producing the super duplex stainless steel coil. The coil is then leveled and tension-straightened with a leveling deformation rate of 1% and a tension-straightening deformation rate of 2%. This invention ensures the appropriate duplex ratio in the final high-strength, high-hardness super duplex stainless steel coil, with a yield strength Rp0.2 ≥ 780 MPa, tensile strength Rm ≥ 1100 MPa, elongation A50 ≥ 10%, and hardness HV ≥ 350, fully meeting the high strength and hardness requirements for special coal mining applications.
Jiuquan Iron & Steel (Group) Co., Ltd. Applies for Patent on Composite Strengthened 18-8 Chromium-Nickel Austenitic Heat-Resistant Stainless Steel Production Method
On June 25, 2024, Gansu Jiuquan Iron & Steel Group Hongxing Iron & Steel Co., Ltd. applied for a patent titled “A Composite Strengthened 18-8 Chromium-Nickel Austenitic Heat-Resistant Stainless Steel Production Method,” with application publication number CN118241024A and an application date of March 16, 2024.
This invention discloses a production method for composite strengthened 18-8 chromium-nickel austenitic heat-resistant stainless steel. The method includes the following steps: first, conventional processes are used to smelt and continuously cast austenitic stainless steel slabs for nuclear use. Second, the slabs are fully ground. Third, the ground slabs are heated in a heating furnace and hot-rolled to the target thickness using a medium-thick plate reversible mill, then cooled to room temperature and cut to specified medium-thick plate sizes. Fourth, the medium-thick plates undergo solution treatment in a continuous roller hearth annealing furnace at a temperature of 1150-1180°C, with a solution treatment time coefficient of 6.0-10.0 min/mm, followed by air and water cooling to room temperature. Fifth, the medium-thick plates are stabilized in a continuous roller hearth annealing furnace at a temperature of 850-950°C.
Nippon Steel Corporation Applies for Patent on Ferritic Stainless Steel Sheet
On June 25, 2024, Nippon Steel Corporation applied for a patent titled “Ferritic Stainless Steel Sheet,” with application publication number CN118251510A and an application date of November 17, 2021.
This invention aims to provide a ferritic stainless steel sheet with excellent formability. The ferritic stainless steel sheet is used in a deep drawing process using a punch and die to form a square tube to the target depth. The ferritic stainless steel sheet contains C, Si, Mn, P, S, Cr, N, Al, O, Ti, Nb, Sn, and Zr, satisfying the compositions of the following formulas (1) and (2), with a sheet thickness of 1.0 mm or less and a limiting drawing ratio of 2.30 or more during deep drawing.
(0.4×Al+0.5×Zr+0.1×Ti)/O≥12.0(1)
0.6×Cr+15×Sn+8×Al≥10.0(2)
Jiangsu Yongjin Successfully Applies for Patent on Stainless Steel Bright Annealing Furnace with Strip Deviation Correction Function
On June 25, 2024, Jiangsu Yongjin Metal Technology Co., Ltd. successfully applied for a patent titled “Stainless Steel Bright Annealing Furnace with Strip Deviation Correction Function,” with application publication number CN118241035A and an application date of May 29, 2024.
This invention discloses a stainless steel bright annealing furnace with a strip deviation correction function. The annealing furnace includes a steel coil input machine, a three-way air pump, a heating section, a slow cooling section, a fast cooling correction section, a top turning section, a descending duct, an inspection platform, and a steel strip output machine. The steel coil input machine is fixedly connected to the heating section, which is fixedly connected to the three-way air pump. The heating section is connected to the slow cooling section, which is connected to the fast cooling correction section. The fast cooling correction section is connected to the top turning section, which is connected to the descending duct. The inspection platform is connected to the descending duct, and the steel strip output machine is connected to the inspection platform. This invention pertains to the field of vertical annealing furnace technology and addresses specific defects in the annealing process, significantly reducing defects and improving the production quality of the steel strip.