CWB Welding Inspector Level III Study Guide

CWB Welding Inspector Level III Study Guide Which of the following metals has the highest thermal conductivity? (a) carbon steel (b) stainless steel (c) aluminum - ANSWER (c) The Ellingham diagram (a) is a plot of thermal conductivity against temperature, (b) shows the free energy of oxide formation against temperature. (c) shows the rate of oxidation of metals against temperature. - ANSWER (b) True or False? A metal with a high negative free energy of oxide formation will generally require greater shielding from the atmosphere during welding. - ANSWER True Electricity can be conducted by: (a) atoms and electrons. (b) electrons and ions. (c) only ions. - ANSWER (b) Which of the following elements is often present in submerged arc fluxes to improve arc stability? (a) copper (b) potassium (c) nickel (d) tungsten - ANSWER (b) Thoria is added to tunsten electrodes for what purpose? - ANSWER To increase thermionic emission by lowering the work function. True or False? All pure metals have the same crystal structure. - ANSWER False. Metals generally have one of three basic structures. Which crystal structure(s) is (are) composed of close-packed planes? - ANSWER FCC and HCP