This book provides an insight into current research topics, focusing special attention exactly on welding issues. The presented research work demonstrates that application of synchrotron and neutron radiation in combination with other techniques enables the basic understanding of material-related processes to be extended appreciably. It also shows ways of how to improve new materials and their use in industry. Following on from the 1st workshop in 2009 at BAM Berlin, a 2nd workshop dealing with this subject matter was held in 28-30 November, 2012 in Osaka/Japan with international participation of scientists from sixteen countries. The book includes selected contributions from the various subject blocks, precisely covering issues of practical and immediately implementable benefit to industrial enterprises. Therefore, peer-reviewed papers dealing with the following topics are contained as well:- Phase transformation during welding, metallurgy and material development- Evolution and significance of residual stresses- Investigations into laser and electron beam welding