418 Flashcards
In torch brazing, the filler metal is distributed in the joint as a result of
capillary action
The oxyfuel process in which the base metal is not melted and the filler metal is drawn into a thin joint by capillary action is called
brazing
When brazing and braze welding, which of the following safety precautions must you observe?
Avold skin contact with the flux
The purpose of scarfing is to
remove a surface defect from unfinished steel
To make the best possible welds using oxyfuel equipment, you should
know what metals you are joining
A special concern when brazing ____ is that the filler metal melts at a temperature very near the melting point of the base metal.
Aluminum
Which of the following is a common surfacing material?
Ceramics
Soldering differs from brazing in that soldering
Occurs at lower temperatures
Which of the following must be worn during an oxygen cutting operation?
Goggles with dark lenses
In torch hard facing, the new material melts ______ the surface. In flame spraying, the new material melts _______ the surface
before it reaches; before it reaches
When welding aluminum, you need to remember that aluminum
conducts heat away from the weld site rapidly
When piercing a steel plate with an oxygen cutting torch, which step should be performed first?
Heat the spot to a bright red
When using thermal spraying for shaft repair, which step should be performed first?
Machining
The purpose of postheating is to
reduce stresses in the welded structure
When you weld low-carbon steel, you should
dip the filler rod into the weld puddle
When welding brass, you should use a
Flux
The purpose of using a flux in brazing is to
eliminate oxides from the metal surfaces
Oxyfuel welding and oxygen cutting are alike in that both processes
require lighting the torch with a sparklighter
Electric arc spraying operations require eye protection with a lens shade number of
9 to 12
In oxyfuel weiding, you can control the rate of heat input to the base metal by varying the
speed of the torch
What kind of flame should be used when welding lead? _____ Nickel?_____ Magnesium? ______
Neutral; Carburizing; Carburizing
What is the purpose of hard face welding? _________ What is the purpose of thermal spraying? ______
Rebuild worn areas; Apply a surface coating
The purpose of using a flux in welding and brazing is to
clean the base metal
If you need to cut a metal other than mild steel or medium-carbon steel, you might make a difficult job easier if you
lay a bead of low-carbon steel along the cut line
In preparing aluminum parts for welding, you should _______ the surfaces to be welded.
scrape or file
