The Study Of Water-based Cast Steel Coating’ Spalling Properties

Expandable Patter n Casti ng(EPC) te c hnol ogy i s c onside red to be themost pos sible gre en casti ng t echnol ogy i n2l ce ntur y. The te c hnol ogygre a t l y r e duce t he c ost o f casting and improves the foundr y i ndustr y ’s highenergy consumption, hi gh polluti on proble ms. The casti ng met hod can beused for a wide ranges. High productivity and high economic effi ciency isthe c hara cters of this met h od. Rese arch of Coatings has al wa ys beenconsidered to be vital in the de vel opme nt proc ess of Expandabl e Patter nCasti ng. I t is ve ry i mporta nt to devel op a ki nd of water-base d ca st st eelcoating which can peel from casting automatically in Expandable PatternCasti ng.In t his paper, c oa ting pe eli ng e ffect s of fact ors, for exampl e, thedegre e of sinteri ng, casti ng wei ghts, as well as aggregate per for mance i sstudi ed systemati c ally thr ough ladder compari s on test. Scanni ng e lectronmicr oscope (SEM), electron probe mi cr oanal ysi s, X-ra y di ffra ction (XRD)analysis were used in t he ex peri me nts. The re sults s ugges t：Cast steel coati ng aggregate of coating should match with the pouringte mperat ure, hi gher sli ghtl y than or the same to the pouri ng te mper ature.Ap proximately about one-third of the thickness of sintered layer fo rmed i nthe c oati n g a ft er pouring has good e ffects for peeling from casti ngs.96%quar tz coati ng without Fe2O3has a good e ffect for pour ing t hewei ght of ca sting i s le ss tha n1000Kg and the weight of the model is lessthan10Kg,96quartz c oati ng wit h5%Fe2O3has a good e ffect on t hepromotion of the coating peeling off.Compared to the quartz particles, bauxite particles have porous nature,porous na ture in t h e bauxite coating make the pyrol ysis a ppear i ng i n foa mmodel pr oducts di scha rge d fr om the cavity in the casting processing, theoxidi zing at mospher e of the outside can be access to t he cavity to promotecoating and t he for mation of met al oxides in the int e r fa c e bet we e nsteel-liquid and coating, prompting the coating peeling fr om t he castingsur fac e a fter pouri n g. The cavity of the atmosphere help “FeO” and Al2O3t o for m t hehercynite phas e whi ch has hi gh re frac t orine ss. The pha se can be st able toexist bet ween steel-liqui d and coat ingBecause t he coati n g i s di fferent from the outer layer o f met al at t helinear s hr inka ge ra te duri ng the cool ing process, then promote coatingpeeling fr om the surface of casting automatically.