Bead tempering effects on flux cored arc welding heat-affected zone hardness

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:115527

Kiefer, J H

Bead tempering is a technique used to control the maximum heat-affected zone (HAZ) hardness in the base metal. Applications have included pressure vessel repairs, pipeline hot tapping, and structural welding. Although this technique can be effective if closely controlled, its use as standard welding practice is questionable because precise control of bead placement is required. Experimental design software was used to define a test matrix to evaluate the effects of base plate carbon equivalent, heat input, and weld fusion line proximity on HAZ softening of flux cored arc welds. Some quantitative limits have been identified for the application of temperbead techniques. The results showed that tempering increased with base metal carbon equivalent and temperbead cooling time. An empirical formula was developed that is useful for estimating the amount of HAZ hardness reduction from the plate chemistry, welding parameters, and temperbead placement. The formula can determine the welding conditions needed to achieve a desired hardness reduction. Temperbead techniques can be effective for reducing HAZ hardness where very close quality control of the bead placement is possible. however, the use of bead tempering to pass welding procedure qualifications for standard production welding should be avoided because the level of close control is usually not practical.

• OSTI ID: 115527
• Report Number(s): CONF-9404233--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ARC WELDING
DATA ACQUISITION
HARDNESS
HEAT AFFECTED ZONE
PRESSURE VESSELS
TEMPERATURE DEPENDENCE
TEMPERING