Evaluation of methods to predict safe welding conditions and maximum HAZ hardness in steel welding

Book · Fri Dec 31 04:00:00 EST 1993

OSTI ID:33186

Tronskar, J P ^[1]

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1. Det Norske Veritas Industri Norge AS, Oslo (Norway)

During the last ten years new structural steels of improved weldability have been introduced. In particular structural steels for the fabrication of offshore structures have been greatly improved in this respect throughout this period. These steels have lean chemical compositions which are generally outside the range for which the existing HAZ hardness criteria and the International Institute of Welding carbon equivalent (CEIIW) formula were originally developed. However, there are indications that the BS 5135:1984 method is not satisfactory for low carbon low CEIIW carbon equivalent steels. This paper presents the results from investigations of the weldability of three normalized (R{sub e min} 350 MPa) and three quenched and tempered (R{sub e min} 500 MPa) offshore structural steels. Weldability testing was conducted to study the relative performance of the different steels and to obtain a comparison between the capability of the different methods to predict safe welding conditions to avoid cold cracking in steel welding. Maximum HAZ hardness restrictions are often a point of contention between fabricators and their clients due to the difficulties often experienced in meeting these hardness requirements. Problems meeting maximum HAZ hardness requirements have been encountered for applications where NACE maximum hardness HRC 22 or Vickers HV10 260 have been imposed for materials exposed to sour service in oil and gas production, processing and transportation. Many attempts have been made to develop empirical formulae for the estimation of maximum HAZ hardnesses. This paper presents some of the more successful approaches proposed to date and compares their performance.

• OSTI ID: 33186
• Report Number(s): CONF-930641--; ISBN 0-7918-0785-1
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHEMICAL COMPOSITION
CORRELATIONS
CRACKING
EXPERIMENTAL DATA
HARDNESS
HEAT AFFECTED ZONE
HYDROGEN
MECHANICAL PROPERTIES
OFFSHORE PLATFORMS
STEELS
TENSILE PROPERTIES
WELDED JOINTS
WELDING