Or simply go through the following pages with links to the relevant articles
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The Online Stainless Steel in Construction Information Centre www.stainlessconstruction.com has become available.
This paper contains the full text of the Drinking Water Inspectorate, (DWI), application 56.4.477, published by the Steel Construction Institute in 2002. There are two distinct parts, the Code of Practice and the Operational Guidelines. A comprehensive range of issues is covered, including material selection and approval, design, welding, fabrication, post fabrication cleaning, installation, maintenance and inspection, (construction, commissioning and operation).
The affects of steel composition on the oxidation resistance of heat resisting stainless steels are discussed. The ferritic stainless steels can suffer strength and embrittlement problems. The austenitic types 1.4845, (310), and 1.4835, (253MA), are good all round choices for oxidation resistance. Maximum temperatures for intermittent service in dry air are lower than continuous service for austenitics. Moist air further reduces service temperatures.
Should heat tint discolouration in the heat-affected zone of stainless steel welds be removed? In cases where the application involves an ‘aqueous’ corrosion hazard, the local reduction in sub-surface chromium can affect the corrosion resistance of the steel. The removal of weld heat tint from stainless steel fabrications using acid pickling or electrolytic methods not only improves the overall appearance but is vitally important for restoring the full corrosion resistance of the finished product. As a general rule, if you can see a discolouration on the surface due heat tint, this should be removed as part of good post weld cleaning practice for any stainless steel welded joints. (37)
This publication has been prepared by the BSSA for the RIBA CPD Providers Network. It lists sources of information from the BSSA website, (articles and publications), the Nickel Institute, Steel Construction Institute, Euro Inox, Outokumpu, and the Australian and South African Stainless Steel Development Associations. These are grouped in topics that include Designing for Durability, Surface Finishes, Fabrication, Environmental Issues, Source of Supply, Architectural and Structural Applications.
The original version of European directive 2002/95/EC effectively out-lawed stainless steels and many other materials as no lead, mercury, cadmium, hexavalent chromium, poly-brominated biphenyls (PBB) or polybrominated diphenyl ethers, (PBDE), content was to be allowed in materials that would be part of equipment ‘which is dependant on electric current in order to work properly’. This has now been rectified in the Official Journal of the European Union document C(2005) 3143, 2005/618/EC, published on 18th August 2005, allows maximum levels of 0.1% for all these, except cadmium which is 0.01%, which is the same as in the ELV directive. In stainless steels only the restrictions to the elements lead, mercury and cadmium are relevant. Commercially produced stainless steels can be expected to comply with the amended RoHS requirements, without actual values being measured or declared by the steelmaker or supplier.
Salt spray testing is an accepted method for assessing the suitability of stainless steel parts and fabrications that are likely to encounter chloride environments in service. The test outcome is sensitive to the shape of the parts, (designed-in crevices), surface finish and the test conditions and so specific results for ‘hours to failure’ for steel grades alone is not appropriate. Specified test methods are shown.
SCI Design Guide for stainless steel
The European Directives 76/769/EEC and 94/27/ECC, (12th amendment to 76/769/EEC, dated 30th June 1994), are sometimes referred to as the ‘nickel or jewellery’ directives. There are two separate issues, Body Piercing and Skin Contact. The selection and suitability of stainless steels for these uses is outlined.
The 316 types are used widely in marine applications, but their corrosion resistance in contact with seawater is limited. They cannot be considered ‘corrosion proof’ under all situations. These grades are susceptible to crevice and pitting corrosion, which limits there use in seawater applications. The affects of water chloride levels, flow rates, temperature and oxygen levels are noted and cathodic protection that can be derived from contact with less noble metals such as carbon steels and aluminium. The 304, and more especially the free machining 303 types, should not be considered for seawater service.