Main characteristics of steel rolling safety production
1，Classification of rolling steel Steel rolling is the production process of rolling steel ingots or continuous casting billets produced by steel mills into steel. According to its cross-section shape, the steel produced by the rolling method can be roughly divided into profiles, wires, plates and strips, steel pipes, and special steel products.
Steel rolling methods can be divided into hot rolling and cold rolling according to different rolling temperatures; According to the relative motion relationship between rolled piece and roll during rolling, it can be divided into longitudinal rolling and cross rolling; According to the forming characteristics of rolled products, it can be divided into general rolling and special rolling. Spinning rolling and bending forming belong to special rolling. Rolling, like other processes, is to make metal plastic deformation and make it into a product. The difference is that steel rolling is carried out between rotating rolls. There are two categories of rolling mills, the main equipment of rolling mills or the main train of rolling mills, auxiliary machines, and auxiliary equipment. Equipment used to deform metal in rotating rolls is usually called main equipment. The operation line formed by the arrangement of main equipment is called the main train of rolling mill. The main train consists of three parts: main motor, rolling mill, and transmission machinery.
Rolling mills are classified according to their uses: blooming mills and opening mills, section mills (large, medium, small, and wire rods), plate and strip mills, steel pipe mills, and other special-purpose mills. Rolling mills are nominal for the diameter of rolls, plate and strip mills are nominal for the length of rolls, and steel pipe mills are nominal for the maximum outer diameter of steel pipes that can be rolled.
2. Main safety technology of steel rolling
(1) Rapid cooling technology of plate after rolling, adopting international advanced laminar cooling device of the high-density tube, improving the production of special steel plate by controlled rolling and controlled cooling technology in plate production, and improving the mechanical properties of steel plate
(2) Controlled rolling and controlled cooling technology in bar production, which realizes temperature controlled rolling of rolled pieces between stands and units through specially designed coolers to improve the strength and toughness of bars, and slitting technology in bar production, which slitts one rolled piece into multiple pieces through specially designed slitting guides or passes. At present, the number of slitting lines is the largest, and there are few steel mills that realize mass production.
(3) Shape control technology of cold rolling, hot rolling, and plate, including design and optimization of roll profile; Online shape detection, signal recognition and shape evaluation of strip plate; Shape control strategy and preset, feedforward and feedback mathematical models.
(4) Hydraulic AGC technology, which adopts high-performance hydraulic APC and AGC control system, has the advantages of fast response speed and high control precision and is replacing electric AGC as the preferred technology for newly built rolling mills and rolling mills to be reformed.
(5) Complete equipment and technology of double stand reversible cold rolling mill. This technology selects different rolling passes according to the material, specification, and production process conditions of the rolled strip so that the rolling mill can flexibly adapt to the changes of strip quality, specification, and coil weight in a large range, and the product precision is high, which can develop precision strip and non-ferrous metal foil.
(6) Complete sets of equipment and technology for hot-rolled narrow strip production, close to wide strip steel in technology and equipment, replace looper oscillator and vertical coiler with laminar cooling and horizontal coiler, and add high-pressure water descaling before roughing mill so that the surface quality and performance of strip steel are obviously improved, and the coil weight can reach 1-2 tons.
(7) On-line surface quality detection system based on image processing, The system uses a CCD camera to collect the surface images of products on the production line, and analyzes and processes the images in real-time through image processing and pattern recognition algorithm, so as to detect whether there are defects on the surface of products and obtain the information such as the size, position, type and grade of defects, so as to achieve the purpose of online evaluation and control of product surface quality.
(8) Steel product development and performance optimization technology, including the influence of process parameters on the formability of IF steel; Study on ultra-fine grain and high strength pure steel: Study on high strength microalloyed (Ti, Nb, V, B) steels.
(9) The analysis software package of ORBIS. This software package WRODES (Wire Rod Online Dimension Examining System) is developed by C + +. The system is easy to install, fast, stable and reliable, has a good man-machine interface, supports automatic report generation and printing, and has the functions of statistical analysis, historical record playback, and inquiry.
(10) The application of finite element simulation in the metallurgical industry, adopting the method of secondary development on the general finite element software ANSYS, the finite element software DEFORM for volume forming and heat treatment analysis, and the thin plate forming analysis software DYNAFORM, makes the development of new products and the improvement of existing processes more scientific and reliable.
3. Precautionary measures and technology of steel rolling production accidents
Before the overhaul, organize overhaul personnel and safety management personnel to make safety preparations, and strengthen safety supervision during overhaul. Pay attention to unsafe factors. In addition to safety precautions, the maintenance site should be equipped with surrounding inspection, safety net, barrier, and safety signs. Seat belts must be worn when working at height.