Bambanci tsakanin jiyya na phosphating da passivation a cikin karafa ya ta'allaka ne a cikin manufofinsu da hanyoyin su.

Phosphating hanya ce mai mahimmanci don rigakafin lalata a cikin kayan ƙarfe.Makasudinsa sun haɗa da samar da kariya ga ƙarfe mai tushe, yin aiki azaman firamare kafin zanen, haɓaka mannewa da juriyar lalata yadudduka, da aiki azaman mai mai a sarrafa ƙarfe.Phosphating za a iya kasasu uku iri dangane da aikace-aikace: 1) shafi phosphating, 2) sanyi extrusion lubrication phosphating, da kuma 3) ado phosphating.Hakanan ana iya rarraba ta da nau'in phosphate da ake amfani da su, kamar su zinc phosphate, zinc-calcium phosphate, iron phosphate, zinc-manganese phosphate, da manganese phosphate.Bugu da ƙari, phosphating za a iya rarraba ta zazzabi: high-zazzabi (sama da 80 ℃) phosphating, matsakaici-zazzabi (50-70 ℃) phosphating, low-zazzabi (a kusa da 40 ℃) phosphating, da kuma dakin-zazzabi (℃ 10-3) phosphating.

A daya hannun, ta yaya passivation ke faruwa a cikin karafa, kuma menene tsarinsa?Yana da mahimmanci a lura cewa wuce gona da iri wani lamari ne da ke haifar da mu'amala tsakanin lokacin karfe da lokacin warwarewa ko kuma abubuwan abubuwan da suka faru tsakanin fuska.Bincike ya nuna tasirin lalatawar injina akan karafa a cikin yanayin da ba a so.Gwaje-gwajen sun nuna cewa ci gaba da zubar da saman karfe yana haifar da gagarumin canji mara kyau a yuwuwar karfe, yana kunna karfen a cikin yanayin da ba a so.Wannan yana nuna cewa wucewa wani lamari ne na tsaka-tsakin fuska da ke faruwa a lokacin da karafa suka haɗu da matsakaici a ƙarƙashin wasu yanayi.Passivation Electrochemical yana faruwa ne a lokacin rashin daidaituwa na anodic, wanda ke haifar da canje-canje a cikin yuwuwar ƙarfe da samuwar ƙarfe oxides ko gishiri akan saman lantarki, ƙirƙirar fim mai wucewa da haifar da wucewar ƙarfe.Keɓancewar sinadarai, a gefe guda, ya haɗa da aikin kai tsaye na abubuwan da ke haifar da iskar oxygen kamar HNO3 mai da hankali akan ƙarfe, samar da fim ɗin oxide a saman, ko ƙari na ƙarfe mai sauƙin wucewa kamar Cr da Ni.A cikin wucewar sinadarai, ƙaddamar da ƙarar wakili na oxidizing bai kamata ya faɗi ƙasa mai mahimmanci ba;in ba haka ba, yana iya ba zai haifar da wucewa ba kuma zai iya haifar da rushewar karfe da sauri.