Fatigue Performance of Advanced High-Strength Steels (AHSS) GMAW Joints

Conference · Thu Jan 01 04:00:00 EST 2009

DOI:https://doi.org/10.4271/2009-01-0256· OSTI ID:965854

Feng, Zhili ^[1]; Sang, Yan ^[2]; Jiang, Cindy ^[2]; Chiang, Dr. John ^[3]; Kuo, Dr. Min ^[4]

---

1. ORNL
2. AET Integration, Inc
3. Ford Motor Company
4. MIttal Steel

The fatigue performance of gas metal arc welding (GMAW) joints of advanced high strength steels (AHSS) are compared and analyzed. The steel studied included a number of different grades of AHSS and baseline mild steels: DP600, DP780, DP980, M130, M220, solution annealed boron steel, fully hardened boron steels, HSLA690 and DR210 (a mild steel). Fatigue testing was conducted under a number of nominal stress ranges to obtain the S/N curves of the weld joints. A two-phase analytical model is developed to predict the fatigue performance of AHSS welds. It was found that there are appreciable differences in the fatigue S/N curves among different AHSS joints made using the same welding practices, suggesting that the local microstructure in the weld toe and root region plays non-negligible role in the fatigue performance of AHSS welds. Changes in weld parameters can influence the joint characteristics which in turn influence fatigue life of the weld joints, particularly of those of higher strength AHSS. The analytical model is capable of reasonably predicting the fatigue performance of welds made with various steel grades in this study.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: EE USDOE - Office of Energy Efficiency and Renewable Energy (EE)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 965854
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BORON
GAS METAL-ARC WELDING
MICROSTRUCTURE
PERFORMANCE
STEELS
TESTING
WELDING