Technical Library
You can refine the list by selecting a sub category:
Or simply go through the following pages with links to the relevant articles
- page 1
- page 2
- page 3
- 4
- page 5
-
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.
-
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.
-
Site location is the initial consideration in selection of stainless steels for external applications. These are classified as rural, urban, industrial or marine. Micro-climates can influence the steel type selection. Other factors that influence the selection are surface finish, design, fabrication methods, accessibility for cleaning and maintenance and mechanical and physical properties of the steels. The main steel types 304 and 316 only are considered for UK external applications. (102)
-
Dry chlorine gas should not attack stainless steels. Damp gas or chlorine dissolved in water can be a corrosion hazard. Corrosion can take the form of localised crevice and pitting corrosion. Stress corrosion cracking, (SCC), can be an additional hazard in damp chlorine gas, if the temperature is high enough.
-
Hydrochloric acid lacks the oxidising properties that stainless steels need to maintain their ‘passive’ corrosion resistant surface layer. Stainless steel have limited resistance. Building mortar cleaners that contain hydrochloric acid can result in staining and pitting to nearby stainless steel items.
-
Sodium Hydroxide, (Caustic Soda), is a strong base, used widely for cleaning metals. Stainless steels types 304 and 316 can be considered resistant below 80 degC, up to the limit of solubility. There can be a risk of stress corrosion cracking, (SCC), attack at higher temperatures.
-
Sodium Hypochlorite is widely used as a sanitiser in water systems and is the main constituent of household bleach, at around 5.25 %. It is aggressive to stainless steels. Pitting or crevice corrosion can occur on most stainless steel grades. Pitting corrosion has been reported from household bleach spills on stainless steel, (304 type), sinks in domestic environments. There is an additional risk of stress corrosion cracking, (SCC), at higher temperatures.
-
Steel grades A, (410, 1.4006), B, (1.4021), C, (1.4028), D, (1.4034), E, (1.4116), F , G, H, I, K, (1.4122), R, L, (1.4105), M, (304, 1.4301), N, (303, 1.4305), O, (301, 1.4310), and P, (316, 1.4401) of BS,EN,ISO 7153-1:2001, (BS 5194-1:1991), are shown. The surgical and dental applications for these grades are outlined. These include cutting and non-cutting instruments and fitting parts and assemblies. (Body implants are NOT covered here.) Corrosion resistance, corrosion testing and the affects on these surgical steels of sterilisation practices are covered.
-
Stainless steel grades, such as the 304 or 316 types are generally suitable for storing and handling cold or unheated drinking (town’s) waters. Hot water tanks however may be at risk from stress corrosion cracking (SCC) Austenitic types such as 304 or 316 can be useful and are used, but in extreme cases the more ‘SCC’ resistant duplex stainless steels should be considered.
-
Finding an unusual grade of stainless steel can be a difficult prospect. This guide is intended to help the enquirer to find anything from the low Cr ferritic grades to the highly alloyed austenitic and duplex steels.
