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QUALITY ASSURANCE GUARANTEE

Galvanising, Inspection and Quality Control will be carried out by the company in accordance with AS/NZS 4680:2006 current issue.

The Standards together with The Galvanisers Association of Australia's manual "Hot Dip Galvanising" will serve as the sole reference material in any dispute concerning galvanising, inspection or quality control.

Specification of hot dip galvanising

AS/NZS 4680 is the Australian/New Zealand Standard for hot dip galvanized (zinc) coatings on fabricated ferrous articles. It specifies the requirements of the coating and includes information on coating mass and thickness, appearance and freedom from defects as well as suitable repair methods.

Coating thickness

Table 1 and Table 2 of AS/NZS 4680 state the requirements for coating thickness and mass, which are based on the steel article thickness.

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Inspection

Inspecting galvanised steel is a simple process. Zinc will not adhere to or react with unclean steel; therefore, a visual inspection of the product provides a good assessment of the quality of the coating. The coating thickness is usually tested using a magnetic thickness gauge. The testing and sampling requirements are contained in the appropriate specification for the product (AS/NZS 4680 and AS 1214).

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Inside of Craigieburn Train Maintenance Facility.

Freedom from defects

A galvanised coating should be continuous, adherent, as smooth and evenly distributed as possible, and free from any defect that is detrimental to the stated end use of the coated article. The integrity of the coating can be determined by visual inspection and coating thickness measurements. A galvanised coating should be sufficiently adherent to withstand normal handling during transport and erection.

Durability of hot dip galvanised coatings

Hot dip galvanizing has proven to be more serviceable and predictable than all other steel protective coatings in the Australian atmosphere. Its excellent performance is due to its inherent corrosion resistance, high tolerance to mechanical damage and inertness to the high UV levels prevailing over all of Australia.

The corrosivity of particular environments have been widely researched and the corrosion rates of both steel and zinc are classified in International and Australian Standards as a function of the temperature, relative humidity, the amount of airborne salinity and the amount of airborne pollution present.

The life of a hot dip galvanized coating is (to a first approximation) proportional to its thickness, which is normally a function of the article’s steel thickness.

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