Heat Source Characteristics of Ternary-Gas-Shielded Tandem Narrow-Gap GMAW
Abstract
:1. Introduction
2. Methods
2.1. Experimental Setup
2.2. Computational Model
- (1)
- The molten metal is an incompressible Newtonian fluid.
- (2)
- The flow of the fluid is laminar.
- (3)
- The droplet is spherical and transfers at a constant speed.
3. Results and Discussion
3.1. Heat Source Characteristics for Narrow-Gap Welding
3.2. Effects of Shielding Gas on Heat Source
3.3. Heat Sources under Different Shielding Gases
4. Conclusions
5. Perspectives
- (1)
- The narrow-gap welding arc properties under different ternary shielding gas compositions can be studied by numerical simulation.
- (2)
- The effects of the gas mixtures compositions on the weld microstructure and mechanical properties is a valuable research issue.
Author Contributions
Funding
Conflicts of Interest
References
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Wire Feed Speed (Lead/Trail) (m/min) | Pulse Frequency (Hz) | Pulse Period (ms) | Peak Voltage (V) | Base Current (A) | Welding Speed (mm/min) |
---|---|---|---|---|---|
10/10 | 220 | 2.0 | 34 | 60 | 300 |
Weld | Ar (%) | CO2 (%) | He (%) |
---|---|---|---|
1 | 90 | 10 | 0 |
2 | 80 | 10 | 10 |
3 | 70 | 10 | 20 |
4 | 90 | 5 | 5 |
5 | 85 | 10 | 5 |
6 | 75 | 20 | 5 |
Nomenclature | Value | Nomenclature | Value | ||
---|---|---|---|---|---|
Solid density | ρs/(kg m−3) | 7990 | Liquidus temperature | TL/(°C) | 1460 |
Liquid density | ρl/(kg m−3) | 7200 | Solidus temperature | TS/(°C) | 1413 |
Temperature coefficient of surface tension | dσ/dT /(N m−1 °C−1) | −0.00035 | Radiation emissivity | ε | 0.8 |
Latent heat of fusion | Hf/(J kg−1) | 2.75 × 105 | heat transfer coefficient | hconv/(W m−2 K−1) | 100 |
Viscosity | μ/(Pa S) | 0.006 | Room temperature | T0/(°C) | 25 |
Surface tension | σ/(N m−1) | 1.8 | Permeability of vacuum | μ0/(B H−1) | 1.2566 × 10−6 |
Wetting angle | θ/(°) | 15 |
Temperature (°C) | 20 | 250 | 500 | 800 | 1000 | 1500 | 1700 | 2500 |
---|---|---|---|---|---|---|---|---|
Specific Heat (J kg−1 K−1) | 460 | 480 | 530 | 675 | 670 | 660 | 780 | 820 |
Thermal Conductivity (W m−1 K−1) | 50 | 47 | 40 | 26 | 28 | 50 | 140 | 142 |
Gas Mixer | ηh | a1 (mm) | a2 (mm) | b (mm) | c (mm) |
---|---|---|---|---|---|
90%Ar-10%CO2 | 0.5 | 3 | 4 | 3 | 3 |
80%Ar-10%CO2-10%He | 0.6 | 3.3 | 4.5 | 3.3 | 3.2 |
70%Ar-10%CO2-20%He | 0.65 | 2.8 | 3.6 | 2.8 | 2.9 |
90%Ar-5%CO2-5%He | 0.52 | 2.6 | 3.3 | 2.6 | 2.8 |
85%Ar-10%CO2-5%He | 0.55 | 3.1 | 4.2 | 3.1 | 3.1 |
75%Ar-20%CO2-5%He | 0.54 | 2.4 | 3 | 2.5 | 3.2 |
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Cai, X.; Dong, B.; Lin, S.; Murphy, A.B.; Fan, C.; Yang, C. Heat Source Characteristics of Ternary-Gas-Shielded Tandem Narrow-Gap GMAW. Materials 2019, 12, 1397. https://doi.org/10.3390/ma12091397
Cai X, Dong B, Lin S, Murphy AB, Fan C, Yang C. Heat Source Characteristics of Ternary-Gas-Shielded Tandem Narrow-Gap GMAW. Materials. 2019; 12(9):1397. https://doi.org/10.3390/ma12091397
Chicago/Turabian StyleCai, Xiaoyu, Bolun Dong, Sanbao Lin, Anthony B. Murphy, Chenglei Fan, and Chunli Yang. 2019. "Heat Source Characteristics of Ternary-Gas-Shielded Tandem Narrow-Gap GMAW" Materials 12, no. 9: 1397. https://doi.org/10.3390/ma12091397