Howtodealwithwhiterustforgalvanizedsteelpipes?
Whatiswhiterust?
Haveweeverencounteredthisphenomenon?Whennewlycoatedhot-dipgalvanized partsarestoredandtransportedinadenseandpoorlyventilatedenvironment,whiteor graypowderycorrosionproductswillformonthecoatingsurface,commonlyknownas whiterust.
1.Analysisofthereasonsfortheformationofwhiterustonthesurface ofgalvanizedpipes:
Whengalvanizedpipescomeintocontactwithair,theirsurfacewillbeoxidized,forminga fragileoxidefilmthatcanserveasaprotectivefilmtopreventfurtheroxidation.However, ifstoredunderhighmoistureconditionsintheairforalongtime,waterwillbeusedasthe medium,causingcarbondioxide(C02)tocombinewithzinctoformwhiterust.
WhiterustformsaftersoakingindeworrainwaterEspeciallyduringstorage,themoisture generatedbycondensationwillalmostcausewhiterust
2.Treatmentmethodforrustformation:
Wewilldividethewhiterustofhot-dipgalvanizedrectangularpipesintothefollowing levels:mild,moderate,severe,andextremelysevereForeachlevelofwhiterust,wewill carryoutcorrespondingtreatmentworkonsuchpipes:
(1)Mildandmoderatecanbeeasilywipedoffwithadrytowel,andwemust thoroughlycleanthesteelpipeswithvinegarandanylonbrush.Afterathorough cleaning,wecandrytheminthesun.
Thewhiterustsituationinthepracticalapplicationofhot-dipgalvanizedsquarepipesis mainlyofmildandmoderategradesSoduringthespecificconstructionproject, experimentswereconductedusingdrytowels,stiffnylonbrushes,vinegar,andother items.Mostwhiterustcanbeeasilyremovedwithadrytowel,whileafewareasrequire vinegarandnylonbrushesAfterthoroughremoval,rinseanddrythetrusswithclean water.
Itcanbeleftuntreatedifwefindverymildrust;weonlyneedtochangethestorage environment
(2)Rustremovalandhotdipgalvanizingarerequiredforheavyloads. Severeandhighlyseverephenomenaarecausedbyimproperstorage,andgalvanized pipesshouldbetreatedimmediately.Iftherustistough,itshouldbecheckedtoseeifthe internalsteelisdamagedIfitisonlyasurfacephenomenon,wemustremoverustand re-galvanize.Iftheinteriorsteelpipehasrusted,theentiresteelpipeshouldbe consideredfordisposalAfterall,manysteelpipesareusedinconstructionandare relatedtolifesafety,andcarefulhandlingisnecessary
3.Howtopreventtheoccurrenceofwhiterust:
(1)Surfacetreatmentcanreducethecauseofwhiterust
(2)Weshallstorethegalvanizedsteelpipesinadryandwell-ventilatedenvironment
(3)Ifthegalvanizedsteelpipesareonlystoredoutdoors,theyshouldbeseparatedfrom thegroundframebyanarrowstriptofacilitatethesupplyoffreelymovinggastothe surfaceofallplatedparts
(4)Galvanizedsteelpipesshouldnotbeplacedinareashighlylikelyaffectedbyrain,fog, coldweather,andsnow
(5)Whenhot-dipgalvanizedsteelpipesaretransportedbysea,theyshouldnotbe transportedasgoodsontheship'ssurfaceorplacedonthehulltopreventcontactwith thebilgewater
(6)Regularinspectionrequiresspecialattention.Duetotherelativelylowamountof internalgalvanizinginhot-dipgalvanizedpipes,whiterustoftenoccursinsidethesteel pipes,whichmaybeneglectedduringtheinspection.