week 1 Flashcards
What do we call a mixture of two or more elements in a metal?
Alloy
What element determines the basic properties of steel?
Iron
Stainless steels are defined by the presence of
Chromium
The ability of a metal to resist penetration is called
Hardness
The ability of a metal to be stretched into thin wire is called
Ductility
ATSM specification for steel products starts with the letter “A” means what
Ferrous metals
What does metal do when its heated
Expands
List the different ways to identify a metal bar
Appearance test, hardness test, magnetic test, chisel test, fracture test, flame or torch test, spark test
Name the five basic weld joints
Butt, corner, lap, tee, edge
One of the major differences between gas fusion welding and brazing is, that in brazing
The base metal is not melted
Which of the following are distinguishing features of a carburizing flame
Two inner flame cones and an outer blue envelope
identify the oxygen-acetylene flame in order from the coldest temperature to the hottest temperature
Carburizing, neutral, oxidizing
when the edges of two pieces of metal are heated until they flow together it is called
Fusion welding
To safely move a pressurized cylinder short distances it can be
placed on a cylinder cart designed for this purpose
What serious condition is indicated when a torch emits a loud and shrill squeal or hissing sound
flashback
what are bits of slag, flux, oxides, or dirt trapped inside a weld called
inclusions
when torch welding, what metal would produce the most hazardous fumes
galvanized
to what group of metals is oxygen - acetylene cutting confined to
ferrous metals
When storing oxygen and acetylene cylinders they can
not be stored together at all
if you believe that you have a problem with an oxygen regulator you
should replace it or have it repaired by a qualified repair person
The thicker the metal the smaller the tip orifice required for welding
false
Use of grease or oil on an oxygen - acetylene unit can cause an explosion
true
the higher the carbon content in steel the lower the melting point
true
when installing a regulator on a gas cylinder cracking means
opening the valve on the cylinder slightly then closing before installing regulator
in a welding shop you should assume that all work and or tools are hot
true
acetylene fittings have special right hand threads
false
you may use a flame to check for leaks on a regulator and hoses
false
quenching is the process of cooling metal slowly
false
an edge point is considered on of the strongest welded joints
false
the standards for proper ventilation for welding areas are set by cal fed
false
the cooling rate of metal is a factor in heat treatment of steel
True
the last two numbers of the AISI number system for steels indicate chemical properties
false
what is the basic principle of oxygen-acetylene flame cutting
a chemical reaction process called oxidation aided by heat
The point where the weld face meets the base metal is called the
toe
oxygen with a regulator can be use in or with
none of the above
in any oxygen-acetylene cutting operation one of the major safety hazards is the
all of the above
low carbon steel is harder that high-carbon steel
false
The metallurgical composition of the filler and the ___ ___ should be close to the same metals
base metal
a metal that is harder than a file has a Brinell hardness number of what
600+ BHN
Welding equipment should be operated in a well ___ area
ventilated
how is density of a metal measure
weight
When oxygen-acetylene cutting is performed excessive slag is a indication of
cutting speed is to slow
the cutting action takes place when ___ comes in contact with the red molten metal
oxygen
what shade lens is used for oxygen-acetylene welding of mild steel
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