Thecoreisthemetalcoreoftheelectrode.Inordertoensurethequalityofweld,therearestrictregulati***onthecontentofallkindsofmetalelementsintheweldingcore.Especially,therearestrictrestricti***onharmfulimpurities(suchassulfur,phosphorus,etc.),andthequalityofweldingcoremetalshouldbesuperiortothatofbasemetal.A***oothrodwithoutacoatingcannotbearcwelded.Thisisbecausethearcstabilityispoor,spatterisverylarge,weldformationisnotgood.Afteralongperiodofpractice,itisgraduallyfoundthattheperformanceoftheelectrodeisgreatlyimprovedbycoatingsomemineralmaterials(thatis,electrodecoating)ontheoutsideoftheweldingcore.)