Chapter 16 Test

_____ has the poorest heat resistance and electron emission characteristic of all of the tungsten electrodes.

Pure tungsten

Which of the following is true of erosion of the tungsten electrode?

Slow erosion results in limited tungsten inclusions in the weld.

How must tube-type and ball-type flowmeters be mounted?

Vertically

_____ is denser that air, so it effectively shields welds in deep grooves in the flat position.

Argon

The square-wave provides the welder with a current that allows the molten weld pool to _____.

Have both deeper penetration and faster solidification.

Which of the following is an inert gas?

Helium

_____ additions are restricted to stainless steels because it is the primary cause of porosity in aluminum welds.

Hydrogen

Tungsten electrodes that contain elements such as lanthanum and yttrium are referred to as _____.

Rare Earth tungstens

DCEP concentrates ______ of the arc heat on the plate, and _____ of the heat on the electrode.

1/3, 2/3