Qabel wieġeb dangalvanizzazzjoni question, let's have a basic understanding the composition of the steel. First of all, the predominant element is iron, and it's soft and ductile. By adding around 0.5 percent carbon to iron, it can dramatically increase tensile strength of the iron. In addition to carbon, manganese also increases hot working properties and increases hardenability and toughness of steel. In general, alloy steels have different material properties which lead to different mechanical performance. Oxygen reacts with and consumes the carbon, to solve this problem, silicon is added to iron as a deoxidizing agent. With excessive quantity of silicon, it can create rough galvanization coating.
Il-fosfru huwa permess b'livell massimu sa {{0}}.04 fil-mija, jekk ogħla minn 0.04 fil-mija, jista 'jżid it-tendenza li l-azzar jinqasam waqt l-iwweldjar u joħloq kisjiet galvanizzati mhux maħduma. Kemm il-fosfru kif ukoll is-silikon jistgħu jaġixxu b'mod sinerġiku biex jikkawżaw tkabbir mgħaġġel ta 'saffi ta' liga taż-żingu-ħadid f'kisjiet galvanizzati minħabba li jaġixxu bħala katalisti matul il-proċess ta 'galvanizzazzjoni. Ir-ritratt hawn taħt huwa eżempju tipiku ta 'wiċċ galvanizzat mhux maħdum ikkawżat minn kontenut eċċessiv ta' silikon.
Biex jinkiseb wiċċ ta 'galvanizzazzjoni tal-ħoss, skont ASTM A385 jew ISO 1461, dawn l-elementi importanti jeħtieġ li jinżammu f'livell elenkat hawn taħt:
√ Ckontenut ta' arbon inqas minn 0.25 fil-mija
√ Manganese inqas minn 1.3 fil-mija,
√ Silicon inqas minn {{0}}.04 fil-mija jew bejn 0.15 fil-mija u 0.24 fil-mija
√ Posfru inqas minn 0.04 fil-mija .
What if silicon content is not in line with the above suggested range, and what could happen to the galvanization? The answer lies in the Sandelin Curve The conclusion is rather clear, and slope is very steep when the silicon is around {{0}}.05 percent , and this level of silicon content usually lead to very thick zinc coating thickness with dull grey appearance. Based upon Sandelin Curve, the recommended limits for silicon is either below 0.04 percent or between 0.15 percent and 0.24 percent .
In reality, lots of galvanizers don't really care that much about either silicon content or Sandelin Curve, and they primarily use dipping time to control the galvanization thickness. This wrong practice normally lead to lots of difetti tal-galvanizzazzjoni, such as rough surface, thin galvanization coating which is not in line with ISO 1461 requirement.
Il-kontenut ta 'silikon it-tajjeb jista' jkollu ħxuna tal-kisi tal-ħxuna u tal-ħxuna ħafna, u jista 'jipprovdi protezzjoni tajba kontra l-korrużjoni, u għalhekk offshore,agrikoltura, akkwakultura, telekomunikazzjoni, minjieri u mina projects require very accurate control on silicon content.
Attwalment, ċertifikat tal-mitħna tal-azzar se jgħin galvanizzaturi biex jiffiltraw il-materjal mhux kwalifikat li jkungalvanizzar bis-sħana, and it will save costs for both galvanizers and the steel fabricators.
