Summary
Asteelplategalvanizedabout1mmzinconsurface,hasthefunctionofcorrosionprotection,widelyusedintheconstructionindustry,thiskindofzinccoatedsteelsheetiscalledgalvanizedsheet.Galvanizationisthemostcommonwaysappliedtopreventrusting.Abouthalfoftheworld'szincproductionisusedinthetechnology.
Classificationanduse
Accordingtotheproductionandprocessingmethodscanbedividedintothefollowingcategories:
1.Hot-dipgalvanizedsteelsheet.Dipthesheetsteelintothemoltenzincbath,athinsheetofsteelbondedtoitssurface.Atpresent,continuousgalvanizingprocessisadopted,thecoiledsteelplateiscontinuouslydippedintothezincplatingbathtomakegalvanizedsteelsheet;
2.Alloygalvanizedsteelsheet.Thesteelplateisalsomadebyhotdipping,butimmediatelyafterthebathisremoved,itisheatedtoabout500DEGCtoformanalloyfilmofzincandiron.Thiskindofgalvanizedsheethasgoodcoatingtightnessandweldability;
3.Electro-zincsteelsheet
Thegalvanizedsteelsheetmadebyelectroplatinghasgoodprocessability.Butthecoatingisthinnerandthecorrosionresistanceisnotasgoodashot-dipgalvanizedsheet;
4.Singleanddoubledipgalvanizedsteelplate.Singlegalvanizedsteelplateisonlygalvanizedononeside.Inwelding,coating,rustprevention,processingandotheraspects,ithasbetteradaptabilitythandoublegalvanizedsheet.Inordertoovercometheshortcomingofthesinglesidezinccoating,thereisagalvanizedsheetwithathinlayerofzincontheotherside,thatis,doublefacedgalvanizedsheet;
5.Alloyandcompositegalvanizedsteelsheet.Itismadeofzincandothermetalssuchasleadandzincalloyandevencompositeplatedsteelplate.Thesteelplatehasexcellentcorrosionresistanceandgoodcoatingperformance.
Accordingtotheusecanbedividedinto:generaluse,theroof,buildingstructure,lateralplate,corrugatedboard,withtensileanddeepdrawingwithgalvanizedsteel.
Galvanizingstandard
ThisstandardreferstoISO3575:1996"commercialgrade,fixedformingstageandstampinggradecontinuoushot-dipgalvanizedcarbonsheet"
ISO41996,structuralgradecontinuoushot-dipgalvanizedcarbonsheetsteelandDINEN10142：2000“Technicalspecificationforcontinuoushot-dipgalvanizedstructuralsteelsheetandstrip”，DIN10147：2000“ColdforminglowcarbonsteelcontinuoushotdipgalvanizedsteelsheetandstripTechnicalspecification”，consideringthespecificcircumstancesofthecountry，“GB/T2518-1998,continuoushot-dipgalvanizedsheetsteelandsteelstrip”hasbeenrevised.
Appearance
1.Surfacestate:duetothedifferenttreatmentofgalvanizedcoatingprocess,thesurfacestateofGalvanizedsheetisdifferent,suchasordinaryzincflower,finezincflower,levelingzincflower,nozincflowerandphosphatingsurface.TheGermanstandardalsospecifiessurfacegrade.
2.Galvanizedsheetshallhaveagoodappearanceandshallnotbeharmfultotheuseoftheproduct,suchasnoplating,holes,cracksandscum,morethanplatingthick,abrasions,chromicacidstains,whiterustandsoon.Foreignstandardsarenotveryclearaboutspecificappearancedefects.Whenordering,somespecificdefectsshouldbelistedonthecontract.
Qualityinspectionstandard
Thequalityrequirementsofthefinegalvanizedsheetincludespecifications,dimensions,surface,zinccontent,chemicalcomposition,plateshape,machineperformanceandpackaging.
1.Packing
Itisdividedintotwokinds:galvanizedsheetwithfixedlengthandzincplatedwithcoil.Generally,tinpackagingwillbelinedwithwaterproofpaperandtiedwithironhoops,tiedfirmlytopreventinsidegalvanizedplatefrictionwitheachother.
2.Size
Theproductscales(asbelow)shallbemarkedwithgalvanizedsheet,recommendedthickness,lengthandwidth,andallowabledefects.Thewidthandlengthoftheplateandthewidthofthecoilcanalsobedeterminedbytheuser'srequest.
3.Surface
Generalsituation:galvanizedcoatingprocessindifferentprocessingmethodbecauseofdifferencesin,suchasordinaryzincflower,finezincflower,flatzincflower,nozincflowerandphosphatingtreatmentofthegeneralsituation.
4.Zincplatingcapacity
Galvanizingscale:theamountofgalvanizingisawidelyacceptedmeansofindicatingthethicknessofthezinccoatingonthegalvanizedsheet.Therearetwokindsofthesameamountofzinc(equalthicknessGalvanized)andtheamountofzincplatingonbothsidesofthedifference(thatis,differentialgalvanizing).Theunitofgalvanizingcapacityisg/m2.
5.Machinefunction
(1)tensiletest:Generallyspeaking,aslongasthelayout,stretchinganddeepdrawing,galvanizedsheetwithtensilefunctionrequest.
(2)bendingexperimentisanimportantitemtoweighthefunctionofsheetmetal.However,therequirementsofvarioustypesofgalvanizedsheetsaredifferentindifferentcountries.
6.chemicalcomposition
Therequirementsforthechemicalcompositionofthegalvanizedsubstratearedemarcatedbythevariouscountries.
7.Plateshape
Weighingtheshapeoftheplate,therearetwoobjectives:flatnessandsicklebend.Thestraightnessoftheplateandthemaximumallowablevalueofthesicklecurvemustbedelineated.
