Weld metal and HAZ toughness of thick structural steel weldments

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:205437

Hannerz, N E ^[1]

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1. Royal Inst. of Technology, Stockholm (Sweden). Division of Welding Technology

Crucial for fracture safe design is the toughness of the weldments, i.e. the heat affected zones and the weld metals. The base metal properties can more easily reach the desired levels of toughness. It appears that where an offshore project specification mentions CTOD requirements it concerns the base steel at {minus}10 C. However, in later stages of the project retesting can be ordered on the HAZ {minus}10 C, CTOD properties, i.e. the same very requirements as those of the base material. Also HAZ hardness requirements have caused trouble with some microalloyed steels where hardness cannot be annealed out. Maximum weld metal nickel content is another example. Fatigue, which must be taken into consideration already at the 350 MPa yield strength level, will increase when steels with levels above 420 MPa are used. One way to get around problems is to use steel castings in the nodes. Some interesting features of research into CTOD of high strength steel weldments obtained in the Nordic countries are reviewed. Single pass Gleeble simulation of HAZ and weld metal may in the future be used to evaluate the lowest thick weldment toughness in terms of CTOD. Also cored wire hydrogen content requirements are discussed as preheat may be determined from the weld metal cracking point of view when low E{sub w} TMCP steels are welded. Preheat is effectively an increase in heat input which affects the toughness.

• OSTI ID: 205437
• Report Number(s): CONF-950695--; ISBN 0-7918-1309-6
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
FRACTURE PROPERTIES
HEAT AFFECTED ZONE
MATERIALS TESTING
OFFSHORE PLATFORMS
STEELS
WELDED JOINTS