Shougang Zhixin Electromagnetic Co., Ltd. has achieved precise and effective production of electrical steel, achieving rolling in seconds and with shearing precision down to the millimeter. The company constantly has one eye on the details, striving to make every possible improvement, working cooperatively to tackle problems one by one, and continuously seeking to optimize full-line production and process operations. As a result, ring furnace trolley rotation has already been speeded up by 64 seconds, pickling rolling by 5.5 seconds, and twenty-high roll mill by 334 seconds. Additionally, the rolling shear edge has been reduced by 2mm, the flattening sample inspection has been shortened by 10cm, and the cut length of retracted reel has been reduced by 76%. As of March 25, the cumulative output of electrical steel has increased by 11,900 tons. 

Finish Rolling in Seconds for Ultimate Efficiency

Shougang Zhixin has always strived for excellence, setting itself consistently high standards. The company has also set itself the challenge of speeding up and improving efficiency across the entire production line. The orientation team conducted painstaking investigations, continually asking questions, finding and verifying solutions, finding breakthrough improvements in the original design framework, and forming a three-step plan to optimize the rotation of the ring furnace trolley. The team improved and optimized various processes and operations second by second and step by step, successfully shortening 21 seconds, 15 seconds and 28 seconds for three motions respectively, optimizing the overall production time by 64 seconds. As of March 25, the output of electrical steel has been increased by more than 200 tons. The pickling team tracked and analyzed the typical speed curve of more than 60,000 coils of steel, breaking down dozens of operation steps and accurately identifying the timing of the action performed by each piece of equipment. The speed limit of the roll assist side was increased to 67% and the single coil rolling time was reduced by 5.5 seconds. As of March 25, output of high-grade steel has been increased by more than 1,700 tons.

Shearing by the Millimeter, Achieving Optimum Results

At Shougang Zhixin, value is extracted from every cent and every millimeter. At the same time as speeding up production, the company also aims at improving yield rate while minimizing shearing loss based on advanced domestic and foreign standards, by shortening the shearing edge in centimeters and even millimeters. The finishing and shearing unit’s research team has carried out shearing tests, incrementally reducing shearing length by 1mm and 1cm across different batches and steel grades. By optimizing programs and modifying equipment, they have tackled various challenges, including meeting high equipment precision requirements, edge deviation and edge blocking, achieving stable shearing of 1mm less on each edge. Shearing was trimmed by 2mm in total, which can reduce cutting loss by about 25 tons per month and has created a cumulative benefit of more than 400,000 yuan. The research team from the stretching and leveling unit keeps meticulous records of cutting loss data from coil sample inspections conducted as they come off the line, compares and analyzes the actual usage of those sample items and continuously tracks its quality. Whilst ensuring inspection processes and results are not affected, the research team shortened the export inspection sample by 0.1m, which has reduced cutting loss of more than 1,800m and increased efficiency by 36,000 yuan in the past year. The continuous retreat unit carried out a project replacing inspection samples with welding seam samples, reducing steel coils samples from 5 to 3 pieces and reducing cutting loss by 1.8 meters. On this basis, the unit worked hard to overcome the problem of precise positioning of the weld seam for minimum cutting loss. They merged tailed samples and welded scrap, reducing cutting loss still further, as well as successfully eliminating welding seam waste. As a result, cutting loss length was reduced by 76%, and strip yield increased by 0.04%. Over the past one year since implementation, the project has generated of millions of yuan in cumulative benefits.