AS 4312-2008 pdf free download

AS 4312-2008 pdf free download.Atmospheric corrosivity zones in Australia.
ISO 9223 classifies five atmospheric corrosivity categories based on the corrosion rate of mild steel, as described in Section 2. These same categories are used in Iso 14713 for selection of metallic coatings. although the corrosion of the first two categories are altered slightly. The ISO 9223 categories have been modified slightly for ISO 12944 for selection of protective paint coatings, and this modified classification is used in this Standard. In ISO 12944. the C5 (very high) category is divided into C5-M marine and C5-l Industrial to account for the differing performance of protective coatings in these two environments. even though the corrosion rate of steel may be the same. This has been adopted for this Standard. Furthermore, a Tropical (T) category has been introduced for this Standard to account for the tact that tropical environments degrade organic coatings such as paint at a greater rate than would be inferred from their corrosion rate. Table 3.1 compares the categories adopted in this Standard to those in the various ISO Standards.
The corrosivity categories adopted are described below for Australia. along with typical areas where such categories may be found
3.2 ATMOSPHERIC CORROSIVITY CATEGORIES
3.2.1 Cl: Very Low (Mild steel corrosion rate <1,3 pm/)
Environments in this category are commonly found inside heated or air conditioned buildings with clean atmospheres, such as most commercial buildings. They may also be found in semi-sheltered locations remote from marine or industrial influence, and in unheated or non-air conditioned buildings. While some alpine regions in Australia are nominally in this category, design and micro-environmental factors sill move them into category C2.
3.2.2 C2: Low (Mild steel corrosion rate 1.3 to 25 .Lrn/y)
Macro-environments in this category include dry, rural areas, and other areas remote from the coast or sources of pollution. Most areas of Australia at least 5() kilornetres from the coast would be in this category. which can extend to within one kilometre from quiet. sheltered seas. Most inland towns, such as Canberra, Ballarat, Toowoomba and Alice Springs arc in this category. as are suburbs of cities on sheltered bays (Brisbane. Melbourne. hobart) that are more than one kilometre from the sea. Adelaide is semi- sheltered, and suburbs more than 6 kilometres from the coast in the southern suburbs, through to 3 kilometres from the coast in the northern suburbs are in this zone. Unheated or lion-air conditioned halls where some condensation ma occur. such as warehouses or sports halls, can be in this category. Proximity to the coast is au important factor.
3.2.3 C3: Medium (Mild steel corrosion rate 25 to 50 jim/y)
Macro-environments are mainly coastal areas with low salinity. The extent of the affected area varies significantly with factors such as wind, topography and vegetation.AS 4312-2008 pdf free download.