4

Study on fracture toughness and fatigue crack growth rate of X80 pipeline steel

Reporter: Luo Li

Advisor: Xu Chen

4

Introduction

References

COD gage

目录

4

The plan

Introduction

References

COD gage

目录

总体概况

The plan

4

Introduction

调研方法

Introduction

调研方法

Introduction

X65

X70

X80X100

X120

Introduction

References

MicrostructuralMicrostructural

Crack closureCrack closurePre-strainPre-strain

CriterionCriterionLBBLBB

FADFAD

[1] S.Y. Shin, B. Hwang, S. Kin, S. Lee. Fracture toughness analysis in transition

temperature region of API X70 pipeline steels[J]. Materials Science and

Engineering : A , 2006,429(15):196~204

[2] S.Y. Shin, B. Hwang, S. Kin, S. Lee. Correlation of microstructure and charpy

impact properties in API X70 and X80 line-pipe steels[J]. Materials Science and

Engineering : A , 2007,458:281~289

[3] 赵亚娟 . 针状铁素体型管线钢的显微组织分析 [J]. 南钢科技与管理 , 2007,

(4):7~9

GBF PF

MA

P

References

MicrostructuralMicrostructural

Crack closureCrack closurePre-strainPre-strain

CriterionCriterionLBBLBB

FADFAD

References

References

[1] Cosham, A., Palmer, A., and Hopkins, P., 2003, “An experimental Study of the Effect of Pre-strain on the Fracture Toughness of Line Pipe Steel,” in Proceedings of the 10th International Conference on Pressure Vessel Technology (ICPVT-10), Vienna, Austria, p. 357

[2] Cosham, A., 2001, “A Model of Pre-Strain Effects on Fracture Toughness,” ASME J. Offshore Mech. Arct. Eng., 123, pp. 182–190.

[3] Cosham, A., Hagiwara, N., Fukuda, N., and Masuda, T., 2002, “A Model to Predict the Effect of Pre-strain on the Fracture Toughness of Line Pipe Steel,” in Proceedings of the 4th International Pipeline Conference (IPC 2002), Calgary, Alberta, Canada, ASME, IPC02–27324, B, pp. 1965–1978.

Pre-strain Negative effect

MicrostructuralMicrostructural

Crack closureCrack closurePre-strainPre-strain

CriterionCriterionLBBLBB

FADFAD

References

References

[1] K. Shinobu, H. Naoto, M. Tomoki. Evaluation of Leak-Before-Break (LBB) Behavior For axially Notched X65 and X80 Line Pipes[J]. Journal of Offshore Mechanics and Arctic Engineering, NOVEMBER 2004, 126:350~357

[2] K. Shinobu, H. Naoto, M. Tomoki. Experimental Evaluation of Leak-Before-Break (LBB) Behavior for High-Grade Line Pipes With an Axial Through-Wall Flaw. 21st International Conference on Offshore Mechanics and Arctic Engineering. OMAE2002-28204 pp. 173-180 

MicrostructuralMicrostructural

Crack closureCrack closurePre-strainPre-strain

CriterionCriterionLBBLBB

FADFAD

References

References

[1] M.Hadj Melian, Z. zari, G. pluvinage. Gouge assessment for pipes and

associated transferability problem[J]. Engineering Failure Analysis,

2010,17(5):1117~1126

[2] S. Cicero, V. Madrazo. Assessment of notched structural components

using Failure Assessment Diagrams and the Theory of Critical Distances[J].

Engineering Fracture Mechanics, 2011,78(16):2809~2825

FAD: Failure Assessment Diagram

MicrostructuralMicrostructural

Crack closureCrack closurePre-strainPre-strain

CriterionCriterionLBBLBB

FADFAD

References

References

[1] GB/T 21143-2007 Metallic materials-Unified method of test for

determination of quasistatic fracture toughness

[2] GB/T 6398-2000 Metallic materials-fatigue crack growth rate tests

[3] ASTM MNL27 28-027096-30 Elastic-Plastic fracture : Laboratory

test procedures

[1] Y.P. Kim, C.M. Kim. Near- threshold Fatigue Crack Growth

Behavior and Crack Closure of Natural Gas Pipeline Steels[J].

Procedia Engineering, 2011,10:813~820

 The crack closure phenomenon of the X80 steel in the

low ΔK region is roughness-induced.

建议总结 Proposals

References

COD gage

COD gage

Calibration Setting mm

Calculatedmm

Deviation%

0.1 0.1042 4.2

0.2 0.2056 2.8

0.4 0.4072 1.8

0.6 0.6102 1.7

0.8 0.8116 1.45

1.0 1.0115 1.15

1.2 1.2120 1

1.4 1.4080 0.57

1.5 1.5112 0.75

Scale=2.43

COD gageThe plan

Date Detail

2012.8-2012.11 Read papers. Design COD gage.

2012.11-2013.1 Fracture toughness tests

2013.1-2013.2 Fatigue growth rate tests

2013.3-2013.6 Post-processing and fatigue tests

2013.7-2014.1 Undetermined

2014.2-2014.5 Finish the paper

The plan

Uniaxial tensile Test

Experimental No.

T-H1 T-Z1

Temperature ℃

room temperature

room temperature

Strain rate s-1 0.001 0.001

Under displacement control

The plan

Fracture ToughnessTest Under displacement control at room temperature

Pre-crack TestLoad ratioR

Crack growthΔa(mm)

The max load Fmax (N)

Loading rate mm/min

The loadF (N)

0.1 1.5~3 Calculated 0.3 Calculated

Experimental No. ContentF-H1 F-Z1 Characteristic valueF-H2 F-H3F-Z2 F-Z3 Single sample method

F-H4~11F-Z4~11 Multi-sample method

The plan

1. Introduction

2. References

3. COD gage

4. The plan