Preparation And Properties Of The Peelable Coating For Stainless Steel Equipment In Nuclear Facilities

In this paper,two kinds of water-based peelable coatings are prepared for nuclear industry equipment,among which the peelable decontamination coating is used for nuclear industry stainless steel equipment decontamination;the peelable protective coatings are used for the protection of new equipment in the field of the nuclear industry and the fixation of contaminants in radioactive contaminated equipment.The paper is mainly divided into two parts:The first part is the preparation and properties of the stripping decontamination coatings.Modified acrylic acid was selected as the film-forming substance,and the influence of the type and amount of water-based additives on the properties of the coating was investigated.The effects of Co60γ-ray irradiation on the appearance,gloss,elongation at break,tear strength,and peel strength at 180° of the stripping decontamination coating were investigated.The experimental results show that the modified acrylic acid peelable decontamination coating with stable performance,mechanical properties have a slight decrease,180° peel strength is improved,which can be completely removed before and after irradiation,used as decontamination coating film and protective coating film.The irradiation resistance and mechanical properties of the coating were further improved by adding eight potassium titanate whiskers.Experiments showed that the addition of 2wt% whisker made the film have higher tear strength and moderate peel strength of 180°.The decontamination efficiency of am-241 fixed pollutants was discussed,where the contamination occurred on the stainless steel surface after the corrosion of hydrochloric acid.The results show that the decontamination efficiency of the coating without adding a chelating agent is 23.2%,and the decontamination efficiency of the film with the amino-polycarboxylic acid chelating agent is the highest,reaching 70.2%.At the same time,It was discussed that the decontamination efficiency of the decontamination coating on the loose pollutants where the pollution occurred on the epoxycoated stainless steel surface.The decontamination efficiency without adding a chelating agent was 92.1%,and the decontamination efficiency with amino polycarboxylate was the highest,reaching 99%.The second part is the preparation and properties of the peelable protective coatings.Go was prepared by the Hummer method and characterized by infrared,SEM,and XRD.It discussed The effect of the amount of GO on the properties of the protective coating.And the results show that the contact Angle and corrosion resistance of the film can be improved when0.1wt%GO adding.The effects of titanium dioxide,mica powder,and barium sulfate on the elongation at break tensile strength,tear strength,180° peel strength,electrochemical impedance,and acid and alkali resistance of the coating were investigated,and the optimal dosage of these pigments in the peeling protective coating was determined.The experimental results show that the irradiation resistance of the film is improved after the addition of pigment filler and Go,meanwhile the irradiation rays do not cause significant changes in the infrared absorption peak strength,mechanical properties,and peel strength of the coating,indicating that the film has stable properties and good irradiation resistance.The experimental results show that when the amount of AM-241 contaminant has increased from 0.1ml to 0.4ml,the sealing efficiency of the film is constantly above 98%,which can play a good sealing effect.