Question

21. Make a comparison of welding, adhesive joining, and mechanical fastening in regard to bond strength and service temperature limitations.
22. List four basic types of fusion welds, and draw sketches.
23. Lis any three defects associated with fusion welding, and describe them briefly.
24. Draw a sketch of weld section, and label three zones; namely: base metal, weld metal and heat affected zone.
25. Define power density and include its units, and describe how power density affects size of heat affected zone?
26. Sketch Fe-Fe3C equilibrium phase diagram, and identify the following:
a. Alpha region
b. Gamma region
c. Delta region
d. Eutectic point
e. Eutectoid point
f. Lower critical temperature line, A1

27. Identify the methods that can be employed to minimize the distortion in the welded workpieces.
28. Identify one high power density and one low power density welding process.
29. Sketch a fillet weld, and identify weld size, throat size and convexity or concavity?
30. Two AISI1020 Steel plates 6 mm thick each are to be welded through a T-Joint double fillet weld using
SMAW process. Assume that each leg of the fillet weld is equal to 4 mm, and the weld has a flat face.
Perform the tasks:
a. How much metal in grams will be required to make the welds? Density of steel weld metal is 7.85
g/cm3.
b. How many electrodes will be required to make the weld if diameter of the electrode is 4 mm, and
length is 350 mm? Assume that electrode metal deposition efficiency is 65%.

Answer 1

These are easily explained in the following images.

Q 21)

22) Answer.