Study On Derusting Coating And Its Application On The Thermal Spraying

The descaling agent system of phosphate acid-phytic acid,which have better conversion capacity and rapid conversion rate, was chosen by contrast it with phosphate acid-tannin in the paper. By contrast with the influence of the weight ratio of phosphate acid in different descaling agent on the coating properties, Phosphate acid and tannin quality with a ratio of 10:1 was finally determined as one pack of the derusting primer. The derusting effect and mechanical properties of the coating achieved the best condition when adding the amount of 60%in the derusting primer.By comparison experiments, epoxy resin E-44 was chosen and modified by phosphate acid to acquire a certain degree of infiltration and rust conversion capacity to rust layer; long oil alkyd, which have a certain toughening effect to prime, was chosen as one kind of filming material, High-sub-amino amino resin was also chosen as a cross-linked filming resin. The quality proportion of filming resin in pack was determined. It is modified epoxy resin (30%), alkyd (20%), amino resin (20%), xylene (15%) and n-butanol (15%). Adopting in the above composition of derusting primer, the properties of anti-rust coating were determined as follows:adhesion is the 1st grade, flexility is less than 1mm, the impact strength surpass 50 kgf·cm, water-resistant is up to 260h, brine resistance is 240h.Optimization of three highly efficient pollution-free pigments and the best dosage of three pigments were ascertained by the influence of water and brine resistance on non-sand-blasting primer. Lager granularity padding of proper granularity was chosen to surface treat and chose the content by silane coupling agent KH 560. Influence of the variety and dosage of epoxy and its curing agent on properties of the coating was discussed, and compound epoxy resin E-20 and E-12 as filming material of non-sand-blasting was chosen and low-molecular-weight polyamide as curing agent was also chosen. The composition of non-sand-blasting thermal spraying was ascertained.Morphology of the internal structure of compound coatings was observed by the photographs of metallographic analysis. The results show tha the two layers of the coarse layer and thermal spraying become a mechanical lock, the two coating layers were combined closely by the formed connection of anchor-hold and incrustation. The compound coating obtains salt spray fog resistance reach 1500h.