Welding speed

Fig. 6. Weld pool shape and resultant weld—metal solidification direction, (a) Slow welding speed, (b) Rapid welding speed.

The use of carbon dioxide gas for shielded arc welding with semiautomatic microwire welding equipment has led to welding speeds up to 10 times those obtainable within conventional equipment. No cleaning or wire bmshing of the welds is required (45) (see Welding). 

Aittomated pracesKS use close control of welding parametera such as current ower, weld speed, an lengA, etc. 

Welding Defects Visual, radiographic and/or ultrasonic Indications. Any welded joints. Basic welding problem laminated steel can cause trouble. Electrode manipulation. Control of welding speeds, procedures, careful inspection and nondestructive testing to locate defects for cutting out or repair. 

Figure 3 (submerged arc welded AISI 304 plate) and Figure 4 (P-Al Mg 4,4 UNI 5452 MIG welded plate), both belonging to new vessels, show the presence of porosity (gas bubbles) imputable to a discontinuous welding speed and to high values of process electrical parameters.

Control of welding speeds, procedures, careful inspection and nondestructive testing to locate defects for cutting out or repair. 

Welding method Pass No. Welding current, A Arc voltage, V Welding speed, m/h Wire feed speed, m/h... 

Alloys from all three classes, a, P, and a P, have been successfully friction stir welded at the University of South Carolina. 2 mm thick sheets of a-Ti, Ti-15V-3Sn-3Cr-3Al and Ti-6A1-4V have been FS welded at a welding speed of lOOmm/min at a tool rate of 200 rpm. The CP-Ti and the Ti 15-3-3-3 were welded using z-axis load control. Load control welding on Ti-6-4 was not stable, so that alloy was welded using position control. The P-transus temperatures for the three alloys are CP-Ti= 915°C, Ti-6-4= 995°C, and Ti-15-3-3-3= 770°C. 

M. Fukumoto, and T. Shinoda, Friction Stir Welding Between Aluminum and Steel with High Welding Speed, Proceedings of the Fifth International Conference on Friction Stir Welding, Sept 14-16,2004 (Metz, France), TWl, paper on CD... 

M. Peel, A. Steuwer, M. Preuss, and P.J. Withers, Microstructure, Mechanical Properties and Residual Stresses as a Function of Welding Speed in Aluminum AA5083 Friction Stir Welds, Acta Mater., Vol 51, 2003, p 4791-4801... 

Fig. 4.3 Transverse yield and transverse tensile strengths of 5454-H32 friction stir welds produced at a range of welding speeds...

Spindle rotation rate, rpm Welding speed, mm/s 2-axis load, kN... 

Fig. 4.6 power vs. welding speed for welds made using three different advances per revolution (APR), (b) Specific... 

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