This set of Welding Interview Questions and Answers focuses on “Metallurgy of Weld”.
Explanation: A multi run process causes a good amount of grain refinement. With every proceeding run weld, it normalizes its previous run. In ordinary steels, grain refinement takes place in the second run.
2. What is the minimum strength of mild steel arc welds on addition of microelements in the slag?
a) 43 kgf/mm2
b) 39 kgf/mm2
d) 48 kgf/mm2
Explanation: When there is an addition of some microelements in the slag along with a few materials being present which are not metals, there is an increase in the strength of the mild steel arc weld. The minimum amount of strength goes up to 43 kgf/mm2, which is 430 N/mm2.
3. Which of the following is affected by weld contour?
c) High pressure property
d) Low pressure property
Explanation: The contour present on the welds form notches. The contours in the form of notches then affect the low temperature properties of the structure and also the fatigue properties.
4. Thermite contains which metal?
Explanation: The reaction that takes place in between compounds and elements is known welding with solid reactants. These reaction are exothermic, that is give out heat as a product. Thermit reaction is a common example for this, which is mixture of aluminium and rust.
a) Solid solubility
b) Liquid solubility
c) Gas solubility
d) Flame solubility
Explanation: The amount of solubility of gas in liquid or solid welded metals is considered to be an essential criteria for the control of porosity of the weld. The gas reactions which occur, then regulate porosity.
6. Slag used in fusion welding contains manganese.
Explanation: Slags used in welding are generally a combination of silica materials and some carbonate compounds. In fusion welding, some amount of bead control has to be done, which is done by the slags, for this purpose, to improve its performance, microelements like manganese are added.
7. Which of the following property is responsible for weld metal cracking?
c) Temperature conditions
d) Pressure conditions
Explanation: The stresses which get developed in welding during shrinkage are of importance. These stresses are considered to be an important factor which are responsible for the cracking that occurs in metal welds.
8. A thermit reaction produces heat up to what temperature?
a) 53 kgf/mm2
b) 49 kgf/mm2
d) 61 kgf/mm2
Explanation: When there is an addition of some microelements in the slag along with a few nonmetallic inclusions, there is an increase in the strength of the mild steel arc weld. The maximum amount of strength goes up to 57 kgf/mm2, which is 570 N/mm2.
10. Slag used in fusion welding has nitrogen.
Explanation: Slags used in welding are generally a combination of silica materials and some carbonate compounds. In fusion welding, some amount of bead control has to be done, which is done by the slags, for this purpose, to improve its performance, microelements like nitrogen are added.
Sanfoundry Global Education & Learning Series – Welding.
To practice all areas of Welding for Interviews, here is complete set of 1000+ Multiple Choice Questions and Answers.