Or simply go through the following pages with links to the relevant articles
Page 5 of 5
- page 1
- page 2
- page 3
- page 4
When it comes to comparing simple surface roughness Ra values, it is possible to make the wrong conclusions, particularly when comparing different types of surface. John Swain of Anopol explains how this can happen
Terne coatings are hot dip lead-tin alloys on a stainless steel substrate strip. Alternatively electroplated tin coatings are allowed by EN 502 and EN 508-3. The strip thicknesses are usually between 0.4 and 0.8mm. The main application for terne and tin-coated strip is external cladding and roofing.
An overview of electropolishing by John Swain of Anopol Ltd, an experienced exponent of the electropolishing process
This 12 page paper by Chris Baxter, Group Technical Market Support, AvestaPolarit Ltd. covers the issues of distortion during fabrication and welding, control of stainless steel welding processes and post fabrication cleaning. Buckling distortion can result from either poor design or welding practices. The key factors for good welding are clearly defined welding procedures, (BS EN 1011 and BS EN 287 and BS EN 288 are mentioned), control of heat input, temperature control and cleanliness. Welding electrode selection and methods including TIG, MMA, FCA, plasma, submerged arc and stud welding are covered. Finally, the importance of careful heat tint removal, (temper coloured areas), is discussed by either mechanical abrasion or chemical pickling cleaning methods is discussed. Although this establishes the corrosion resistance for the particular grade welded, care is needed with chemical pickling as it can change, (dull), the aesthetic appearance of the surfaces.
The corrosion resistance of stainless steels is derived from the alloying element chromium. A chromium-rich oxide film forms naturally on the surface of the steel. If damaged, the film will normally repair itself. In this condition the steel is in the passive state. If the film is destroyed the surface is in the active state.
The importance of good design and surface finish selection for the successful fabrication of stainless steel is outlined along with some of the properties that can affect the fabrication and performance of stainless steels. These include thermal conductivity, thermal expansion coefficient and the risks of galling, (pick-up). The hazard of iron contamination from carbon steel pick-up is mentioned and that welding oxide or heat treatment scale should be removed prior to service.