Subscribe to our newsletter to receive the latest news and events from TWI:

Subscribe >
Skip to content

Can I use rutile or cellulosic electrodes for welding steel that could suffer from HAZ hydrogen-induced cracking?


Frequently asked questions

If there is a risk of hydrogen-induced cracking, then the primary recommendation is to use low hydrogen consumables. However, provided that all the factors which can influence the formation of hydrogen cracks are considered, it is possible to use either rutile or cellulosic electrodes for welding such steels.

Hydrogen-induced cracking can occur if hydrogen, tensile stresses and a susceptible microstructure are all present to a sufficient level. Assuming that tensile stresses will always be present to some degree, hydrogen-induced cracking is more likely as a result of the higher levels of hydrogen present in rutile/cellulosic electrodes, especially when welding more hardenable crack-sensitive steels.

However, the likelihood of hydrogen-induced cracking occurring will differ with the nature of the fabricated components and, in particular, the carbon equivalent of the steel and the welding procedure. This is because the HAZ microstructure is dependent on the steel composition and the cooling rate. It will, therefore, be influenced by the thickness of material, the joint design, the heat input during welding and the level of preheat/interpass temperatures and times. Using electrodes with a medium-high hydrogen potential, it may still be possible to weld a given component if its design is considered, together with the options of controlling heat input and pre-heat.

Line-pipe girth welds are commonly deposited with cellulosic electrodes. An important mitigating factor in reducing the cracking risk in the root region is the deposition of a hot pass that refines the microstructure of the root weld bead and its associated HAZ before it cools to a sufficiently low temperature that hydrpgen-induced cracking could have ocurred.

Whilst you would not consider repair welding a medium carbon steel forging using rutile or cellulosic electrodes, a low heat input and no preheat; it would be possible to weld the same material using the same electrodes if it was in sheet form, using an adequate level of heat input and preheat. If there is any doubt in avoiding cracking, joint simulation testing should be carried out, especially for critical applications.

Guidelines for avoiding hydrogen cracking may be obtained from publications such as 'Welding Steels Without Hydrogen Cracking', 2nd Edition, Abington Publishing Ltd, Abington, Cambridge, 1993 (ISBN 1 85573 014 6), or Standards such as BS EN 1011-2: 2001 'Welding - Recommendations for welding of metallic materials: Part 2 Arc welding of ferric steels'. (This Standard has replaced 5135: 1984 'Arc welding of carbon and carbon-manganese steels'.)

For more information please email: