- freely available
Metals 2016, 6(11), 281; https://doi.org/10.3390/met6110281
2. Materials and Experimental Techniques
3. Results and Discussion
3.2. Mechanical Properties
- The initial microstructure of the steel used in this study consisted of ferrite and pearlite structure. However, the weld metal of all welded samples has polygonal ferrite and plate ferrite near the HAZ. Widmanstatten ferrite and a small amount of martensite was also observed in the center of the weld metal.
- An increase in the welding current caused an increase in the heat input. As a result of this, samples welded at higher welding currents showed a wider HAZ compared to the samples welded at lower welding currents.
- The highest ultimate tensile strength was measured as 665 MPa in the sample S2, welded at a welding current of 400 A. This is due to the formation of Widmanstaten ferrite in the transition area of the welded joints. An increase in the welding current raised the heat input which encouraged the formation of Widmanstatten ferrite.
- The highest hardness of 281 HV, 297 HV and 320 HV was obtained in the weld metal for samples S1, S2 and S3 respectively. In general, as the welding current increases, it is possible that more widmanstatten ferrite or martensitic structure can be formed in the weld center because of large austenite grains and a high cooling rate.
Conflicts of Interest
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|Oerlikon S2 (SAW wire)||0.08||0.6||1.3||0.025||0.025||-||-||-||-||-||-|
|Sample No.||Welding Parameters|
|Current (A)||Voltage (V)||Welding Speed (cm/min)||Heat Input (kJ/mm)|
|Sample No.||Yield Strength (MPa)||Ultimate Tensile Strength (MPa)||Elongation (%)|
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