Research Of The Causes And The Way Of Boiler Corrossion Of Steel

Boiler works in the conditions of high temperature and high pressure,at the same time, the pressure part of the fire (smoke) side are under the action of the smoke, air, ashes and water vapor, leakage water; Water side are under the action of the high salinity boiler water, scale, high temperature steam and carbon dioxide, oxygen, and so on, so the working condition of boiler is very poor, the surroundings are corrosive,so the producing Of corrosion is a very common phenomenon for boiler. Meantime, Boiler is a kind of explosilve equipment which has destructive power, accordingly, the dangerousness of its corrosion is also big. This paper writes about the causes and the way of boile corrossion of steel through analysis from some cases encountered in writer’s everydaywok of boiler inspection.in the process, some test means which include internal inspection, material examination, chemical analysis, water quality analysis, spectral inspection, scanning electron microscope and X-ray diffraction analysis were used.Aspect of design and manufacture:the phenomenon such as circulation flow stagnation zone, discontinuous structure zone, composite stress or stress concentration shoud be reduced or avoided as far as possible;try to choose good performance, strong corrosion resistance steel;Set the correct water quality sampling points correctly, sampling device and sampling point should ensure that the samples are representative; the drum (shell) exposed to hearth should be adiabatic;Installation:Continuous drainage should be a cut-off valve in series with the control valve, control valve should be kept open during operation after proper adjustment.Operation:the process of adding coal shoud be even and smooth; the process of heating and cooling and Rev. Stop furnace shoud be slow;avoid temperature and stress fluctuate too fast so that the metal appear the phenomenon of fatigue; strengthen pollution discharge in the correct way; select the type of boiler reasonably according to the operation mode.Management Aspects:To make water quality indicators meet the standards,chose the corresponding water treatment method according to different water and boiler type; allocate qualified, card holder of water quality laboratory technician;SO42-Can cause corrosion,In the process of water quality analysis, CL-, SO42-can be harm to the same extent;Take the correct boiler stop maintain method,And in turn the boiler water put dry, clean scale and soot, drying, and desiccant, airtight manhole, hand hole door hole;Attention should be paid to the staffing, card-holding, daily training work of Special equipment operators, requirements for related management personnel can not be ignored; to discover the situation and the degree of corrosion timely, periodic inspection shoud be done Seriously and timely, so as to take measures to eliminate hidden danger of accidents.