hp series grinding roller open arc surfacing welding anti-shedding welding method

Abstract

The invention discloses a high-pressure (HP) series grinding roller open arc surfacing anti-dropping welding method. The method is characterized by comprising the step of pre-welding treatment. The pre-welding treatment includes a first step of cleaning and polishing the surface of a grinding roller, namely installing an iron brush on an angle grinder to polish the grinding roller, eliminating a corrosion layer on the surface of the grinding roller until a metal body is revealed out of the whole surface of the grinding roller, and ensuring that the surface of the grinding roller is free from greasy dirt, corrosion and impurities and meets requirement of the welding process, and a second step of carrying out coloring and ultrasonic flaw detection before automatic surfacing is carried out to the grinding roller, checking whether the abnormal phenomena of cracks, casting defects, localized wear and the like happen to the grinding roller, and inspecting chemical components and mechanical properties of the grinding roller according to DL / T681rules. According to operation characteristics and wear characteristics of the HP series grinding rollers on a machine, the first reasonable surfacing hardness is within 58-64 and can not be too high, and running time can reach 12000 hours. Consequently, stability of operating of the HP series grinding rollers on the machine can be guaranteed. Surfacing again can be repeated for six to seven times as long as the welding process is consistent with welding materials.

Description

technical field [0001] The invention relates to the technical field of grinding rollers of HP series coal mills in thermal power plants, and relates to an anti-falling welding method for open arc surfacing welding of HP series grinding rollers. Background technique [0002] In recent years, the rapid development of China's economy has driven the rapid development of the thermal power industry. HP-type coal mills are increasingly used in the pulverization system of new large-scale generating units, especially 600MW and 1000MW units. The key to HP-type coal mills The parts are HP series (including HP1163, HP1003, HP863, HP783, HP983, HP963, etc.) grinding rollers. [0003] Different raw materials have different degrees of wear on the grinding rollers, and the life of the grinding rollers is also different. The wear of HP series grinding rollers in thermal power plants is mainly due to the three-body high-stress abrasive wear on the grinding rollers caused by coal and some har...

AI Technical Summary

Problems solved by technology

Compared with open arc welding, submerged arc welding has the disadvantage of drying the flux before welding, adding flux continuously during the welding process, and requiring a special person to remove the welding slag, which makes the manpower and material resources invested in the surfacing process very high. Due to the impact of welding slag, the grinding roller cannot be forcedly cooled to maintain the normal temperature between welding layers, which limits the weldability of the grinding roller

[0006] The above two conventional welding processes and methods will cause the surface of the surfacing layer of the HP series grinding rollers to fall off after welding. If the pre-welding inspection is not thorough or the welding process is not handled properly, it may also cause the grinding rollers to crack. Not scrapped, etc.

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