The 1,580mm hot rolling production line of Jingtang Company passed the standard smoothly a few days ago, marking that the biggest annual repair task of Jingtang Company was successfully completed since it was put into operation by the No. 1 Metallurgical Construction Branch of Shougang Construction Group.

As for this series of annual repairs, Shougang Construction Group undertook a total of 1,903 maintenance items, of which there were 131 items in the Material Supply Department, 291 items in the Iron-making Department, 697 items in the Steelmaking Department, 152 items in the Hot Rolling Department, 316 items in the Color-coated Board Business Department, 180 items in the Energy Department and one item in the Coking Department. These items were respectively implemented by 7 specialized maintenance and inspection companies under the No. 1 Metallurgical Construction Branch, the spare parts processing center and the Mechanical and Electrical Engineering Project Department.

After being assigned the task, the No. 1 Metallurgical Construction Branch immediately organized the management backbone, and analyzed and arranged the six maintenance contents of the Iron-making Department, the Steelmaking Department, the Hot Rolling Department, the Energy and Environment Department, the Material Supply Department and the Color-coated Board Business Department of the overall maintenance items in Jingtang. In order to facilitate the unified coordination and command, on the basis of meeting the requirements, the No. 1 Metallurgical Construction Branch established the annual repair item headquarters, and 6 professional functional groups, such as the maintenance control room and the spare parts material group. 7 maintenance and inspection branches, namely, blast furnace and steelmaking, the spare parts processing center and the Mechanical and Electrical Engineering Project Department, were responsible for the implementation. The branch headquarters was set up, and the general headquarters coordinated and allocated the resources such as manpower, equipment and tools in a unified way.

In terms of the technique, according to the maintenance items and the time node arrangement, the No. 1 Metallurgical Construction Branch organized the technical personnel of each unit to get familiar with the drawing, study the equipment technical data, master the operation state of the equipment and the technical standards required during the construction, make clear the construction procedure flow, and carefully formulate the construction plans of the key projects undertaken by them ahead of time. In the aspect of preparation of construction machines and tools, all professional companies implemented and reported the plans one after another according to the items and came in one after another before the maintenance to ensure adequacy of construction machines and tools during the maintenance. As for quality management and control, set up a quality control group to strictly control, guarantee the quality and ensure the realization of the predetermined objectives. During the construction, they need to do a good job in process control and item control. All maintenance items should go through self-inspection and mutual inspection of the groups. After meeting the qualification, they should also receive the special inspection of the technical quality group and the written acceptance record should be formed. On the basis of “the three-inspection system”, it is necessary to conduct the supervision and inspection of the equipment engineering room of the Operation Department and the Equipment Department to ensure that the maintenance items were completely qualified. In the aspect of safety and security management, according to the arrangement of the No. 1 Metallurgical Construction Branch, headquarters of the two levels shall establish a safety and security group to supervise and inspect the implementation of the quantitative standard of safety production and ensure the realization of “no in four aspects”, namely, no minor personal injury or above, no fire, no equipment damage, and no lost spare parts and accessories and “two guarantees,” that is, guarantees of zero violation and zero accident. In the aspect of standardized maintenance, headquarters of the two levels need to arrange special people to supervise the standardization of this maintenance, strictly carry out the management regulations of Jingtang Company on civilized production in construction, strictly implement the “6S” management system and the “four-three” standard on the site, emphasize standardized maintenance, civilize production and operating environment standards while emphasizing progress, safety and quality, and achieve civilized production, fixed placement, orderly arrangement, standardized operation and clean site.

It is understood that the annual maintenance not only has taken a long time, covering many maintenance items and cost much manpower but also achieved many breakthroughs. For example, for the first time, 5,500 cubic meters of super large blast furnace with whole band copper cooling stave was replaced. As the maintenance organization and construction technology of the item are mastered only by a few domestic enterprises, the monopoly trend formed gradually. Under the strong support of the leadership of Jingtang Company at all levels and in the face of doubts, Shougang Construction Group spent 23 days and 22 hours in completing 73 copper cooling staves on 2 bands, 856 cooling water pipes and 2,822 welded junctions, realizing the air supply success of No. 2 blast furnace at a time. The maintenance item of assembly and disassembly of fixed-width press machine and fixed-width slide frame on the 2,250mm hot rolling production line was carried out for the first time. It was once thought that only a unit could complete this item. By utilizing the preliminary technical plan, construction and assembly machines and tools, spare parts and other preparatory work, Shougang Construction Group staff strictly controlled the quality and implemented meticulous organization and construction to ensure the success of the heat load test at a time. For the first time, the continuous and alternative annual maintenance of 3 slab continuous casting machines was carried out and the overall maintenance during the complete production termination of the steel-making system was arranged in the middle. Moreover, the G crown block beam key hidden danger elimination item was also completed. 1,835 people participated in the maintenance. The ability of cooperative dispatch of the Shougang Construction Group maintenance system stood the test in the case of extremely difficult construction organization, and the strong maintenance organization and technical support were also demonstrated.