The Effect of Welding Process on the Fatigue Life of Joints made by Diffusion Welding.

Sanjeeb Kumar Samal

Master's thesis

Abstract:

To accomplish a specific task just like any other technology-oriented, the 10GN2MFA steel went for diffusion welding and the welded steel has gone through the fatigue mechanical test. Diffusion welding method used for improving joint interference, especially for fatigue strength, through atomic bonding along bainitic and pearlite microstructures. However, the purpose of the master thesis is to characteristics fatigue behaviour of 10GN2MFA basic and 10GN2MFA welded steel with the constant parameter. The heating and cooling rate of welding, chemical composition, and hardness highly influenced fatigue mechanical strength. The S-N diagram revealed after diffusion weld the 10GN2MFA steel reduced nearly 24% of fatigue strength. On other hands 400 MPa the welded steel fatigue limit could not be obtained even at 105 stress cycles. This test highly influenced towards stress amplitude, where fracture happened in the joint area above endurance limit. These results were compared load to load groups with the same frequency of fatigue cycles. The thesis all main points were discussed in conclusion of this work.

Abstract:

To accomplish a specific task just like any other technology-oriented, the 10GN2MFA steel went for diffusion welding and the welded steel has gone through the fatigue mechanical test. Diffusion welding method used for improving joint interference, especially for fatigue strength, through atomic bonding along bainitic and pearlite microstructures. However, the purpose of the master thesis is to characteristics fatigue behaviour of 10GN2MFA basic and 10GN2MFA welded steel with the constant parameter. The heating and cooling rate of welding, chemical composition, and hardness highly influenced fatigue mechanical strength. The S-N diagram revealed after diffusion weld the 10GN2MFA steel reduced nearly 24% of fatigue strength. On other hands 400 MPa the welded steel fatigue limit could not be obtained even at 105 stress cycles. This test highly influenced towards stress amplitude, where fracture happened in the joint area above endurance limit. These results were compared load to load groups with the same frequency of fatigue cycles. The thesis all main points were discussed in conclusion of this work.

Keywords

Diffusion Welding, Gleeble, 10GN2MFA Steel, Hardness, Microstructure, Fatigue.

Language used: English

Date on which the thesis was submitted / produced: 21. 5. 2018

Thesis defence

• Supervisor: doc. Ing. Jaromír Moravec, Ph.D.

Technical University of Liberec

Faculty of Mechanical Engineering

Master programme / field:
Mechanical Engineering / Engineering Technology and Materiales