"The Welding Research Council Committee on High Alloys is supporting a research project on a problem critical to the electric power industry. It is the need for laser welding repair methods for high-strength@ directionally solidified@ nickel-base superalloys used in turbine components. The success of a new technology will largely depend on consistently achieving the desired microstructure in the deposit zone. The project will identify the optimal laser repair welding conditions that will result in strong deposited fusion zone by systematically studying the process parameters@ fusion zone solidi?cation modes@ and post repair heat treatment. Of course@ a complete understanding of the strengthening mechanisms and metallurgy of this unusual class of materials is essential to solving this problem. To this end WRC has also supported documenting the state of the art with regard to the metallurgy and mechanical properties of this class of materials and components. WRC Bulletin 511@ ""High Performance Cast ??- Strengthened Nickel-Base Superalloys-An Interpretive Report"" This Bulletin@ ""Mechanical Properties of Cast ??-Strengthened Nickel- Base Superalloys"" completes the documention of the technical foundation. The two Bulletins enable evaluation of optimal welding procedures to assure that reliable repair and post welding heat treatment procedures are established. The Bulletins are also useful reference resources for those involved in material selection@ life assessment and design optimization"