Fatigue crack initiation for Al-Zn-Mg alloy welded joint

被引：2

作者：

Zhang, Liang ^{[1
]}

Liu, Xuesong ^{[1
]}

Wang, Linsen ^{[2
]}

Wang, Ping ^{[1
]}

Fang, Hongyuan ^{[1
]}

机构：

[1] Harbin Inst Technol, State Key Lab Adv Welding & Joining, Harbin 150001, Peoples R China

[2] Dongfang Boiler Grp Co Ltd, Welding Proc Sect, Zigong 643001, Peoples R China

来源：

ACTA METALLURGICA SINICA-ENGLISH LETTERS | 2012年 / 25卷 / 03期

关键词：

Al-Zn-Mg alloy; Welded joint; Fatigue crack initiation; Life prediction; DAMAGE MECHANICS; LIFE PREDICTION;

D O I：

10.11890/1006-7191-123-235

中图分类号：

TF [冶金工业];

学科分类号：

0806 ;

摘要：

To investigate fatigue crack initiation characteristics of Al-Zn-Mg alloy welded joint, notched specimens were used in fatigue test for the base metal, welding bead and heat affected zone (HAZ). The fatigue fracture surface near the fatigue crack initiation site was observed by scanning electron microscope (SEM). The results show that the differences of fatigue crack initiation life among base metal, welding bead and HAZ are not obvious. Inhomogeneity in microstructure and mechanical performance of HAZ influences the fatigue crack initiation life. The ratio of fatigue crack initiation life (N-i) to fatigue failure life (N-f) for the base metal, welding bead and HAZ of A7N01 aluminium alloy welded joint are 26.32%, 40.21% and 60.67%, respectively. Fatigue crack initiation life can be predicted using a uniform model. Observation of fatigue fracture surfaces shows that for the welding bead a fatigue crack initiates from the smooth surface due to the welding process, the blowhole in HAZ causes fatigue crack and the crushed second phase particles play an important role in fatigue crack initiation for the base metal.

引用

页码：235 / 240

页数：6

共 10 条

[1] CONTINUUM DAMAGE MECHANICS .1. GENERAL CONCEPTS [J].

CHABOCHE, JL .

JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME, 1988, 55 (01) :59-64

[2] Models for the estimation of weldment fatigue crack initiation life [J].

Hou, CY ;

Charng, JJ .

INTERNATIONAL JOURNAL OF FATIGUE, 1997, 19 (07) :537-541

[3]

Iqbal M, 2000, J MATER SCI TECHNOL, V16, P319

[4] HOW TO USE DAMAGE MECHANICS [J].

LEMAITRE, J .

NUCLEAR ENGINEERING AND DESIGN, 1984, 80 (02) :233-245

[5] Fatigue crack initiation life prediction of railroad wheels [J].

Liu, Yongming ;

Stratman, Brant ;

Mahadevan, Sankaran .

INTERNATIONAL JOURNAL OF FATIGUE, 2006, 28 (07) :747-756

[6] Observations of fatigue crack initiation in 7075-T651 [J].

Payne, Joel ;

Welsh, Greg ;

Christ, Robert J., Jr. ;

Nardiello, Jerrell ;

Papazian, John M. .

INTERNATIONAL JOURNAL OF FATIGUE, 2010, 32 (02) :247-255

[7]

Pilkey W.D., 1997, PETERSONS STRESS CON, P89

[8]

Xue H., 2007, THESIS TIANJIN U TIA

[9]

Yan D.J., 2011, THESIS HARBIN I TECH

[10] Fatigue life prediction for toe ground welded joints [J].

Zhang, Yan-Hui ;

Maddox, Stephen J. .

INTERNATIONAL JOURNAL OF FATIGUE, 2009, 31 (07) :1124-1136

← 1 →