"1) Influences of Steel Composition and Welding Procedure on the HAZ Toughness of Thick-Section Structural Steels by P. L. Harrison and P. H. M. Hart (2) Heat Affected Zone Properties of Thick Section Microalloyed Steels?A Perspective by F. Heisterkamp@ K. Hulka and A. D. Batte (3) Experience in Fabricating New Types of Offshore Plate and Linepipe by P. Tuvnes and I. Harneshaug (4) Influence of Local Brittle Zone on HAZ Toughness of TMCP Steels by S. Aihara and K. Okamoto These four papers contained in this Bulletin were presented at the Conference on ""Metallurgy@ Welding and Qualification of Microalloyed (HSLA) Steel Weldments"" held at Houston@ TX@ November 6-8@ 1990. The American Welding Society holds the copyrights and is the source of these papers. In order to provide further information on the extent of the local brittle zone (LBZ) problem in modern structural steels@ an extensive research project was conducted using a wide range of commercial structural steels (BS4360 Grade 50E types) welded at heat inputs of 1@ 3 and 5 kJ/mm. Particular emphasis was placed on fractographic and microstructural analyses of fractured CTOD specimens in order to identify compositional and microstructural factors influencing low fracture toughness"