Heat-affected zone fracture toughness of 420-500 MPa yield strength steels: Effects of chemical composition and welding conditions
- Det Norske Veritas Industri, Hoevik (Norway)
During the last five years, high-strength steels with yield strengths in the range 420 to 500 MPa have attracted considerable interest within the offshore industry, primarily due to the potential for weight saving and reduction in volume of weld metal through the use of reduced section thicknesses. With respect to chemical composition these steels are developed following much the same philosophy as for the modern normalized structural steels. Due to the increased stress level in these higher strength steels, it is anticipated that brittle fracture initiation occurring in the coarse-gained HAZ will be more critical for these steels than for the lower strength normalized grades. The objective of this paper is to present the results from several experimental investigations carried out at VERITEC during the last five years to study the factors affecting the crack tip opening displacement (CTOD) fracture toughness of the heat-affected zone (HAZ) in structural steels in the yield strength range 420-500 MPa. Typical CTOD fracture toughnesses of the HAZ in normalized 350-MPa yield strength steels used in offshore structures are also presented for comparison. The results of the investigations confirm that the same chemical compositional factors which are known to influence the HAZ fracture toughness of normalized steels are also important for the 420-500-MPa yield strength steels. It is demonstrated that the width of the HAZ is important for the initiation of brittle fracture of pop-in and that this width must exceed a certain minimum value for such events to occur.
- OSTI ID:
- 5950777
- Journal Information:
- Journal of Offshore Mechanics and Arctic Engineering; (United States), Vol. 115:1; ISSN 0892-7219
- Country of Publication:
- United States
- Language:
- English
Similar Records
Production of high strength TMCP steel plate for offshore structures
HAZ fracture properties of Ti-microalloyed offshore steel in as-welded and simulated condition
Related Subjects
BUILDING MATERIALS
MATERIALS TESTING
OFFSHORE PLATFORMS
WELDED JOINTS
CRACK PROPAGATION
ULTIMATE STRENGTH
BRITTLENESS
CHEMICAL COMPOSITION
FRACTURE MECHANICS
STEELS
STRESS ANALYSIS
VERY HIGH PRESSURE
ALLOYS
IRON ALLOYS
IRON BASE ALLOYS
JOINTS
MATERIALS
MECHANICAL PROPERTIES
MECHANICS
TESTING
423000* - Engineering- Marine Engineering- (1980-)
420500 - Engineering- Materials Testing