Description : The EWR headless welding process is an innovative technology developed by the Danieli Group. The process can realize the continuous automatic on-line welding process of the billet on the outlet side of the heating furnace, so as to achieve the uninterrupted production of the subsequent rolling mill. The EWR process has the following advantages: ——increasing the production capacity and equipment... The EWR headless welding process is an innovative technology developed by the Danieli Group. The process can realize the continuous automatic on-line welding process of the billet on the outlet side of the heating furnace, thereby achieving the uninterrupted production of the subsequent rolling mill, and the EWR process has the following advantages: - increase production capacity and equipment utilization; The reason for the above advantages is mainly due to the following reasons: - cancel the interval between billets; The EWR process can be used both for new construction and for retrofitting existing equipment; it can be used to produce both ordinary steel grades and special steel grades. A dedicated solution is available for special installations or spaces where space is limited. Global EWR equipment The first two sets of EWR equipment were put into operation in 1999 at SSB Malaysia and BSI Bar Plant in Thailand. Currently, the equipment has been supplied to the world in seven sets, namely: - Deacero Celaya Bar & Wire Factory (Mexico), the first EWR production line in North America; Another EWR production line will be put into operation at the Harry Wolga Bar Plant in Greece in the summer of 2002. EWR process description The welding process begins at the exit of the billet heating furnace. The slab from the furnace is first descaled, and then the front end is subjected to a flash butt welding process with the end of the billet which has been rolled in the roughing mill. The moving weld head cycle starts from the rest position and then accelerates until it reaches the same speed as the billet. Then, the head of the latter billet is locked to the tail of the previous billet by two clamping devices moving at a speed matching the rolling speed of the first frame, and then the flash butt welder starts welding. . A patented system enables automatic centering of the clamped billet so that the clamp and the four sides of the billet are in full contact, resulting in a more uniform welding current. The welding process first uses direct (DC) high current to melt the ends of the two billets, and then uses external force to squeeze the two melted sections together. It is because of this extrusion process that the ends contain Any inclusions overflow as the molten metal overflows. The welding schedule is selected based on the steel grade, melting temperature, end condition, and section size. The welding equipment is mounted on a moving trolley and can be used for welding billets or round billets of 100 to 200 mm. The steel grades that can be welded include carbon steel and alloy steel (including stainless steel). The flash melting stage is affected by the condition of the end of the billet because it determines the depth of melting required at the end, and the deeper the depth of the melt, the longer the weld cycle. As the welding process is completed, the hydraulic start deburring tool removes all burrs from the weld zone, returning the cross-sectional dimensions of the billet to its original dimensions prior to welding. After the burr is removed, the flash butt welder returns to the initial position to start the next welding cycle, at which time the billet is continuously rolled like a bar. Main advantage 1 Capacity and equipment utilization The production capacity increased by 12%~14%, and the equipment utilization rate was improved by the following aspects: - eliminate the gap time between billets; 2 quality With this EWR headless welding process, uniform product quality is achieved. Maintains a highly uniform geometrical geometry, mechanical properties and technical performance throughout the entire length of the endless rolling stock. 3 material yield With this EWR headless welding process, the material yield can be as high as 99%, mainly because it eliminates the shear of the strip head and tail, eliminates the short rule and short head on the cold bed, and eliminates the roll head and tail. The finishing process and the minimization of the number of occurrences of the stack, the elimination of the short-foot phenomenon is extremely advantageous for the steel producers, because the online straightening equipment can be more effectively utilized. 4 Production costs The savings in production costs vary depending on the capacity of the equipment, but most of them are on average 3.5 to 4.5 Euro/t. The savings in production costs are mainly due to increased production, reduced energy consumption per unit, and service life of consumables. Extension, reduced staffing and simplified management. The reduction in unit energy consumption varies from 2% to 4% (capacity 20 to 250,000 tons) to 5% to 7% (capacity: 70 to 800,000 tons). The investment payback period of the equipment varies depending on the equipment capacity. The EWR headless welding process facilitates production planning and increases production flexibility. It can also result in indirect cost savings. 5 Improve product sales The improvement in product sales is mainly due to the following aspects: ——The product quality is uniform and reproducible; EWR endless rolling process combined with Danieli's other processes The EWR endless rolling process combined with the latest production processes reduces costs, increases productivity and improves product quality. Rolled wire: In conjunction with Danieli's two-module (TMB) technology, the EWR endless rolling process enables ultra-high-speed production of small-size wire rods with a rolling exit speed of up to 120 m/s. Rolled bar: With the new coiling mechanism, the EWR process can realize uninterrupted and twistless coiling of round steel and flat steel. Even if low-weight billet is used as raw material, high-quality, ultra-compact large-volume coils can be produced. (up to 3500kg), which improves the performance of the rolling mill. The coils produced in the above configuration can be directly supplied to the downstream cold processing line. Straight bar: With the Danieli high-speed 2-segment or multi-segment system, the EWR process can fully utilize the productivity and efficiency of the bar mill. Typical characteristics of the EWR process ——Ultra-compact and increasingly integrated design makes welding equipment and simplification, and production and maintenance are extremely efficient; Hand Shower,Retro Design Hand Shower,Anti-rust Hand Shower,High Quality Hand Shower KaiPing HuiPu Shower Metalwork Industrial CO,LTD , https://www.hp-shower.com
- the material yield is as high as 99%;
- reduce production costs (average: 3.5 to 4.5 euros / t);
- Improve production planning and easy factory management.
- no head and tail shearing of the bar during rolling;
- no short rods / short feet and tails;
- no coiling of the wire during the production process;
- reduce the number of occurrences of steel piles;
-- Reduced requirements for repairs, spare parts, and consumables.
——Tangshan Iron and Steel Company Bar Factory, this is China’s first EWR production line;
——The French ALPA bar factory, which is the first EWR production line in Europe;
—— Wuyuan Iron and Steel Company, which is another two EWR production lines in operation in China;
——China Xinjiang Bayi Iron and Steel Co., Ltd. This is the world's first non-head rolling special steel wire production line.
- no short rods and short feet and tails;
- it is possible to set a higher finishing speed;
- Reduce the number of stoppages required for unplanned repairs and reduce the number of occurrences of steel.
——For wire rod mills using low weight billets as raw materials, extremely high coil weights can be obtained;
- For a roll bar or wire production line, the ability to provide the user with the required roll weight.
——The welding machine supplies DC power to obtain a more uniform current distribution across the entire cross section of the billet, which is better for better control of the flash butt welding process, and the DC power supply can minimize the power loss;
- Small billet self-centering clamping system. The clamping system can be in full contact with all four sides of the billet to provide a more uniform current transfer between the fixture and the billet. In addition, the adjustment of the billet is extremely simplified;
——The deburring system between the fixtures ensures automatic and high-precision burrs after welding. The deburring process occurs when flash butt welding is completed and is performed during the weld zone cooling time, which does not impose any additional requirements on the space and has no effect on the operation of the EWR entire line.
- The offline positioning system allows the EWR equipment to be parked near a production line to be serviced and set up without affecting normal production. Therefore, in order to meet the different requirements of various customers, a variety of technical solutions are provided.
——Welding equipment is equipped with protective equipment to prevent flashing effects during flash butt welding and a special brushing system to remove weld defects and flash scars to ensure the welding area is clean.
- A dedicated computer system controls every step of EWR production and guarantees perfect reproducibility. Moreover, switching between the headless welding rolling model and the conventional rolling can be achieved at any time.
Introduction to EWR headless welding process