CTOD Evaluation for HAZ Toughness of Offshore Structure Steels with Heavy Thickness Based on API RP 2Z

Abstract:

The CTOD (Crack Tip Opening Displacement) evaluation and control for HAZ (Heat Affected Zone) toughness of welded joints are the most effective measures to the security of steel structures. This paper address the problem of the newly developed offshore structure steel API 2W 50Z with heavy thickness of 100mm. In accordance with the American Petroleum Institute standard Recommended Practice 2Z (API PR 2Z), the CTOD tests of two critical positions of HAZ in three kinds of heat inputs were carried out in low temperature (-10°C). All of these CTOD testing and assessments are finished under the witness of American Bureau of Shipping (ABS). The result shows that all of the CTOD values are greater than the required value (0.38mm) in API RP 2Z. This indicates that the newly developed offshore structure steel (API 2W 50Z) meet the requirement of the toughness. Further, the CTOD testing and assessments in several international standards about weld joints of steel plates are also compared and discussed in this paper.

• Periodical: Advanced Materials Research (Volumes 634-638)
• Pages: 2916-2922
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.634-638.2916
• Online since: January 2013
• Authors: Ting Miao, Zhang Mu Miao, Ling Hu, Xiang Kui Zhang, Wei Fang Qian
• Keywords: CTOD, Heat Affected Zone (HAZ), Offshore Structural Steel

References

[1] Xueqing Gui. Itinerary map of marine engineering equipment industry development[N]. China Ship News (In Chinese), 2012-7-25

[2] Xuesheng Tang. Offshore structure steel: "outlet at sea" for Chinese steel companies[N]. Chinese Ship News (In Chinese), 2010-2-26

[3] Zhangmu Miao, Qinglin Chen. Low Temperature CTOD Toughness Test for E40-Z35 Thick TMCP Steel Plate[J]. Steel Rolling (In Chinese), (2007), 24(4):P1-4

[4] Zhangmu Miao, Huafang Wu. Toughness of Offshore steel structure and CTOD testing techniques[J]. Steel Structure (In Chinese), (2008), 23(2):P18-22

[5] API Specification 2W: Specification for Steel Plates for Offshore Structures, Produced by Thermo-Mechanical Control Processing (TMCP)[S]. API, (2006)

DOI: 10.1520/a0841_a0841m-03

[6] API Recommended Practice 2Z: Recommended Practice for Preproduction Qualification for Steel Plates for Offshore Structures[S]. API, (2005)

[7] ASTM E1290: Standard Test Method for Crack Opening Displacement (CTOD) Fracture Toughness Measurement[S]. ASTM, (2008)

DOI: 10.1520/e1290-02

[8] British Standard Institution.BS7448:Part1: Method for Determination of KIC, Critical CTOD and Critical J Values of Metallic Materials[S]. London: British Standard Institution, (1991)

DOI: 10.3403/02516822

[9] British Standard Institution.BS7448:Part2: Method for Determination of KIC, Critical CTOD and Critical J Values of Welds in Metallic Materials[S]. London: British Standard Institution, (1997)

DOI: 10.3403/01124251

[10] Offshore Standard.DNV-OS-C401: Fabrication and Testing of Offshore Standard[S]. DNV, (2004)

[11] BS EN10225: Weldable structural steels for fixed offshore structures-Technical delivery conditions[S]. London: British Standard Institution, (2009)

DOI: 10.3403/02338491u

[12] MQPS: Materials and Qualification Procedures for Ships[S]. Lloyds Register, (2002)

[13] Rules for the Manufacture, Testing and Certification of Materials[S]. Lloyds Register July 2009.

[14] Kaifeng Wang, Linghe Meng. Evaluation method for pre-production of offshore structures steels based on API RP 2Z [C]. The 15th China ocean (offshore) engineering conference (In Chinese), (2011)