الفهرس 
INTRODUCTION
Defective Girth WeldsOnly 14 pages are availabe for public view
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Abstract
Thermo-Mechanical Control Process (TMCP) is a process of controlled hot rolling followed by on-line accelerated cooling. Such action increases the strength of the steel as the result of the induced grain refinement. TMCP steels somewhat differ from conventional steels in chemical composition. With the low carbon equivalent they provide excellent weldability. The objective of this study is to investigate the effects of different welding processes on the mechanical properties of TMCP steel, with emphasis on the influence of welding heat input on the designated mechanical properties of the different zones of the weld joints , namely base metal, heat affected zone (HAZ) and fusion zone, and to check whether after welding they still comply to the required design properties of the structure.Two TMCP steel plate specimens 12.7 mm thick were welded by SMAW process using electrode Types E7016-1, E8010-G and E8018-G . In addition, two coupon rings from TMCP steel pipe, with nominal diameter of 24 inch and a wall thickness of 15.9 mm, were welded using GMAW/FCAW processes, with electrode types ER70S2, ER70S6 and E71-T. All plate and ring specimens had ASTM grain size number 9.5 (ultrafine grain structure ).