Welding Inspector Level Iii Study Guide Rated A+

True or False? A metal with a low thermal conductivity is more likely to reach the maximum melting efficiency when welded. {Ans: True}Without referring to the text, draw the phase diagram for a eutectic system with limited mutual solid solubility of the two components. {Ans: Refer to Figure 6.6(Module 20-2014, page 18)}In an electroslag flux the current is carried mainly by: (a) neutral oxides. (b) holes. (c) mobile ions. (d) thermionic electrons. (e) free electrons. {Ans: (c)}Which of the following metals is likely to need the greatest degree of shielding from the atmosphere during welding? (a) copper (b) lead (c) titanium (d) steel (e) gold {Ans: (c)}Hot Cracking during welding is more likely in: (a) pure metals. (b) alloys with a wide solidification range. (c) alloys with a very high alloy content. {Ans: (b)}Thoria is added to tunsten electrodes for what purpose? {Ans: To increase thermionic emission by lowering the work function.}Centerline hot cracking im more likely with: (a) shallow, round welds. (b) short weld pools. (c) wide groove angles. (d) deep, narrow welds. (e) vertical welds. {Ans: (d)}Which of the following metals has the highest thermal conductivity? (a) carbon steel (b) stainless