High temperature anti impact corrosion abrasion resistant silicon carbide coating used in repairing boiler original gas flue:
An Neng pyroelectricity original gas flue anti wear corrosion resistant coating construction
After the boiler flue gas drawing forth from gas flue,it will rise pressure through booster fan,then enter into GGH flue gas heater,after cooling down,
enter into absorption tower,you don’t need to take any measures for the original gas flue front of flue gas heat exchanger,for the desulfurization device
with flue gas heat exchanger,should take measures from side entrance bend part of flue gas heat exchanger original gas flue to the gas flue of chimney,
the selection of corrosion resistant materials should be based on applicable condition,we could use hgh temperature anti abrasion corrosion resistant coating
from Xiangyang City Hundred Shield Coating BD series.
The composite coating for this part should be selected BD427 high temperature corrosion resistant coating and BD776 high temperature impact resistant
silicon carbide epoxy coating,in this combination we mainly take advantage of the high bonding strength features of our BD427,and use it as prime coat
transition layer,before BD427 without curing,should smear BD776 on its surface to form wear resistant coating for high strength bonding metal.
1.Substrates surface treatment: Do roughening treatment on the pending-repair part of original gas flue,grinding with angle grinder or sand blasting etc,
the surface after coarsening treatment should be cleaned,the surface after this treatment should be the one coarsening,dry and fresh substrates,should be
no greasy dirt and dust.
2.Brush coating the corrosion resistant prime coat:The preparation of BD427 high temperature anti corrosion coating according to the specified ratio,
and use it as the prime coat,mainly take advantage of the high bonding strength features of our BD427,and use it as prime coat transition layer,before prime
coat without curing,should smear BD776 on its surface to form abrasionr resistant coating for high strength bonding metal.
3.The preparation of wear resistant coating:According to weight ratio A:B=5 :1, make A and B two components of BD776 high temperature silicon
carbide epoxy coating mix uniformly,and use it up within 30 min.Generally it’s while construction and configuration. Every time the most preparation
quantity is not more than 2Kg,too much adhesive is solidified too fast,hasn’t been used up until partial adhesive has solidified and can’t be used.
According to the actual temperature,configuration can be properly a little more in winter,proper less in summer.If the temperature is too low,
can properly heat up the A component to reduce viscosity for easy to configure.
4.Coating:The suitable coating thickness of BD766 high temperature anti wear corrosion resistant carbide silicone coating is 2-15mm.Make the well
mixed material be coating on the pending-repair part layer by layer, the first layer should be compacted,make it infiltrate fully with the substrates.
Repair the surface to be smooth after the coating is coated in the suitable size,or use low viscosity wear resistant adhesive to be coating on the surface
of the coatings.This material can do machining,if there is the out of tolerance,can do the turning and grinding processing.
5.Curing:It can be put into using after curing for 24 hours at the temperature of 25℃,If the temperature is below 15 degree,the coating can’t be fully
curing,should heat it up to the temperature of 80 degree after the coating initial curing and keep this temperature for 2 hours to promote the coating fully
curing.(can use the iodine tungsten lamp to do irradiation heating with the 40cm distance from the coating).