V4A – corrosion resistant steel
The name V4A is an old designation and stands for chrome-nickel steel with molybdenum additive. Searching for rust-resistant steel, the company Krupp developed, among other things, austenitic rustproof chromium nickel steel. That was in 1912. The letter V stands for the German word for test (“Versuch”) and the A if for austenite. Another, very well-known Material from this group is “Versuchsschmelze 2 Austenit” – or test smelt 2 austenite – or V2A in its shortened form.
V4A is no longer available, but is still used as a term. V4A steel is available in types 1.4401, 1.4404 and1.4571 . These steels are used in the construction industry, in offshore engineering, in chemical tankers and in the food and drinks industry.
Use of V4A in industry
- 1.4404 and 1.4571
are also used in the production of pharmaceutical, synthetic fibre, textile and paper plants as well as pressure vessels.
is very resistant to substances containing chloride due to its molybdenum content. Due to its high strength, this steel is only conditionally suitable for machining methods and only with special tools.
The low carbon content prevents inter-crystalline corrosion (grain disintegration) even after a welding procedure. The steel grade has better machinability than 1.4401 or 1.4571.
The titanium alloy of this steel prevents intercrystalline corrosion even after welding. However, this alloying causes high tool wear in machining methods.
All V4A steel grades can be very easily cold worked, for example, by Bending or deep-drawing.If worked thermally within the temperature ranges 1,030-1,110°C, V4A steels must be solution annealed with immediate quenching with water. If the temperatures are kept to 850-1,150°C , rapid cooling with air is sufficient. Apart from a few exceptions, all the named steel grades can be welded with conventional methods, i.e. TIG,MAG, arc (E), submerged arc welding or even laser beam welding.