120102i Flashcards
What does the term hard facing mean?
A) the application of an alloy that assists corrosion
B) to weld together part that have been quenched
C) To apply a layer of material that combats wear
D) To apply material that is difficult to use
C) To apply a layer of material that combats wear
Machinery parts that are subjected to where can have their service life prolonged by
A) welding with alloy electrodes
B) hard facing the ware surface
C) repairing the parts often
D) using the equipment sparingly
B) hard facing the ware surface
What is a major advantage of hard facing
A) worn parts with high replacement cost can be reclaimed
B) hard facing filler alloys are cheap and easy to apply
C) any hard facing alloy can be used with any welding process
D) the very hard alloys can also withstand high impact loading
A) worn parts with high replacement cost can be reclaimed
Which arc welding process is very popular for hard facing because of its low equipment, cost versatility and general ease of application
A) GMAW
B) SMAW
C) GTAW
D) FCAW
B) SMAW
Which method of hard facing process is the slowest
A) SMAW
B) FCAW
C) GMAW
D) GTAW
D) GTAW
What is a disadvantage of the FCAW surfacing process as compared to GMAW surfacing
A) it produces slag, which may have to be removed
B) cannot be added to the wires
C) the cord electrode can only be used on a small radius
D) the equipment is much more expensive
A) it produces slag, which may have to be removed
What is the advantage of the MCA W surfacing process compared to the FCAW surfacing process?
A) the deposition rates are similar
B) special equipment is required
C) Al cannot be added to the wires
D) it produces little to no slag
D) it produces little to no slag
Which arc welding surfacing method uses high currents and high deposition rates leaves no spatter and emits no harmful ultraviolet radiation
A) SMAW
B) OAW
C) SAW
D) FCAW
C) SAW
Which is true of the oxy fuel, gas hard surfacing process
A) you can surface only large areas
B) the base metal does not have to be clean
C) it has a higher deposition rate than arc surfacing processes
D) it has low base metal dilution
D) it has low base metal dilution
Which statement describes thermal spray surfacing
A) the flame rises the surface so that the rod can be melted onto it
B) the constructed arc is forced between the electrode and the workpiece
C) the electrode is continuous, and the arc is covered with flux
D) it heats a metallic or non-metallic material and propels it towards the object
D) it heats a metallic or non-metallic material and propels it towards the object
A sliding scraping type of wear that removes metal by gouging or grinding is called
A) erosion
B) abrasion
C) corrosion
D) impact
B) abrasion
A gouging type of wear that washes away or grooves out the metal surface is called
A) corrosion
B) oxidation
C) erosion
D) abrasion
C) erosion
A seizing or galling type of wear that rips and tears out portions of a metal surface is called
A) abrasion
B) metal on metal
C) erosion
D) compression
B) metal on metal
The type of wear that pits perforate and eventually dissolves metal is called
Corrosion
A special form of corrosion that results in the crumbling or flaking off of a metal surface is called
Oxidation
A cracking splitting type of wear caused by rapidly, exposing metal parts to rapidly heating and cooling cycles is called
A) thermal shock
B) impact
C) abrasion
D) metal to metal
A) thermal shock
Squeezing type of where usually caused by the imposition of a heavy static load on the surface of a metal is called
Compression
Which material is the most abrasion resistant of all hard facing materials?
A) tungsten carbide
B) chromium carbide
C) austenitic manganese
D) austenitic stainless steel
A) tungsten carbide
Which hard facing material can be Ferrous or non-Ferrous
A) tungsten carbide
B) chromium carbide
C) austenitic manganese
D) austenitic stainless steel
A) tungsten carbide
These hard facing materials allied with 5% – 12% chromium are probably the most widely used
A) semi-austenitic
B) austenitic manganese
C) austenitic stainless steel
D) martensitic stainless steel
A) semi-austenitic
These hard facing materials, which are work, hardenable are well suited for impact loading
A) tungsten carbide
B) chromium carbide
C) austenitic manganese
D) martensitic stainless steel
C) austenitic manganese
For best results, the deposits with these materials should be two or more layers thick
A) tungsten carbide
B) chromium carbide
C) martensitic stainless steel
D) heat, treatable steals
C) martensitic stainless steel
Which material results in a deposit that is hard if cooled quickly or soft and tough if cooled slowly
A) tungsten carbide
B) heat treatable steels
C) austenitic manganese
D) copper alloys
B) heat treatable steels
Which hard facing material is used for sliding metal to metal contact and for corrosion resistant applications.
A) chromium carbides
B) Austenitic manganese
C) heat treatable steels
D) copper alloys
D) copper alloys
What problem can result from the deep penetration characteristics of some ark welding processes
A) the hard facing metal may dilute with the base metal
B) the metal chunks may break away from the base metal
C) the parts may become hardened by heat treatment
D) with preheat, underbead, cracking always results
A) the hard facing metal may dilute with the base metal
Which term describes the breaking away of the weld metal from the base metal
A) dilution
B) distortion
C) falling
D) spalling
D) spalling
What is one method you could use to avoid stress failure when hard facing part hardened by heat treatment
A) use no preheat
B) quench in water right after welding
C) avoid interruptions during welding
D) quench in oil and cover with a blanket
C) avoid interruptions during welding
_____ is the application of a hard, wear-resistant metal or metal alloy to the surface of a softer metal by a welding process.
a) spalling
b) metal to metal
c) hard facing
d) dot pattern
c) hard facing (hard surfacing)
The purposes of _________ are to
* combat wear,
* prolong the life of the object,
* reduce costly down time and
* reduce the cost of replacement parts.
a) spalling
b) metal to metal
c) hard facing
d) dot pattern
c) hard facing
It is more __________ to hardface a new or worn part instead of purchasing a new piece.
a) complicated
b) time consuming
c) economical
d) expensive
c) economical
If parts are badly worn from their original dimensions or shape, they should first be built-up with a suitable material before ________.
a) spalling
b) metal to metal
c) hard facing
d) dot pattern
c) hard facing
If the part is hardfaced with a very hard, brittle material, the soft metal underneath may crush under impact. This could cause cracking and _______.
a) spalling
b) metal to metal
c) hard facing
d) dot pattern
a) spalling
The breaking away of the weld metal from the base metal describes what process
a) spalling
b) metal to metal
c) hard facing
d) dot pattern
a) spalling
______ can be applied using a variety of welding processes to allow the use of different _____ materials.
a) spalling
b) metal to metal
c) hard facing
d) dot pattern
c) hard facing
True or False
Surfacing metals can be wires, rods, filled tubes, strips, granules or powders.
True
* You can also perform surfacing by different arc procedures, oxy-acetylene welding and thermal spray.
* Arc welding is usually used where excessive heat buildup is to be avoided.
What are the top 3 processes used for hard surfacing?
GMAW, MCAW, GTAW, FCAW, SAW, SMAW, OAW, Thermal spray surfacing
GMAW, FCAW, SMAW
Gas metal arc welding equipment may be mechanized, automatic or semi-automatic. The power source output is usually ____.
a) AC
b) DCEP
c) DCEN
d) DC
d) DC
True or False
Alloying elements that produce the hard surface deposit are contained in the electrode or can be added as a powder into the weld puddle.
True
Figure 6 is a GMAW system that has a hopper assembly so that tungsten carbide powder can be added to the weld puddle.
FCAW & MCAW surfacing uses what type of feed rollers?
a) U groove
b) knurled
c) V groove
d) either a or b
b) knurled
This process is sensitive to electrode extension and produces a slag that may have to be removed.
SAW stands for:
a) surface arc welding
b) submerged arc welding
c) standard arc welding
d) staggered arc welding
b) submerged arc welding
SAW has ___________ penetration characteristics and protective flux cover.
a) very shallow
b) very deep
c) relatively shallow
d) relatively deep
d) relatively deep
Due to the protective _______ cover, more heat is added to the work piece than other welding processes. Because of this dilution the full properties of the surfacing metal are not attained until _____ or more layers are deposited.
a) coating, three
b) flux, two
c) flux, three
d) coating, two
b) flux, two
Two advantages of using _____ for hardfacing is that there is no spatter and no exposure to ultraviolet radiation from the submerged arc.
a) GMAW
b) MCAW
c) GTAW
d) SAW
d) SAW
_______ is a popular, low cost, convenient method that uses a covered electrode to deposit the hard surfacing material.
The welding current may be either DC or AC.
a) GMAW
b) SMAW
c) GTAW
d) SAW
b) SMAW
_______ is a low deposition rate process that produces a high-quality deposit with minimum dilution and low distortion.
It is slower than other arc welding methods, and it produces overlays of excellent quality.
a) GMAW
b) SMAW
c) GTAW
d) SAW
c) GTAW
______ does not have the capability for high deposition rates offered by most of the arc welding processes, but the low temperature limits the base metal dilution.
a) GMAW
b) OAW
c) GTAW
d) SAW
b) OAW
OAW hard surfacing process used to apply tungsten carbide
_________ is a process that heats a metallic or non-metallic material to a nearly molten state and then propels it onto an object to be surfaced.
a) metal to metal
b) abrasion
c) thermal spraying
d) hard facing
c) thermal spraying
Distance and heat input are critical with this process.
______ is a sliding/scraping type of wear that removes metal by gouging or grinding.
a) compression
b) impact
c) erosion
d) abrasion
d) abrasion
______ is a pounding or battering type of wear that splits, breaks, chips, mushrooms or otherwise deforms the metal surface.
a) compression
b) impact
c) erosion
d) abrasion
b) impact
_____ is a gouging type of wear that washes away or grooves out the metal surface.
a) compression
b) impact
c) erosion
d) abrasion
c) erosion
________ wear is a seizing or galling (wearing away by friction) that rips and tears out portions of a metal surface.
a) metal to metal
b) impact
c) erosion
d) abrasion
a) metal to metal
______ is the type of wear that pits, perforates and eventually dissolves metal parts.
a) metal to metal
b) corrosion
c) erosion
d) abrasion
b) corrosion
_______ is a special form of corrosion that takes place when some metals are exposed to a combination of heat and air. The resulting wear is a crumbling or flaking of the metal surface.
a) metal to metal
b) corrosion
c) erosion
d) oxidation
d) oxidation
__________ is a characteristic form of oxidation that usually occurs due to an insufficient amount of purging gas used during welding
a) compression
b) oxidization
c) sugaring
d) thermal shock
c) Sugaring, it also looks like granules of sugar are stuck to the weld.
__________ is a squeezing type of wear usually caused by a heavy static load or by loads that gradually increase pressure on a metal surface. This pressure can cause a metal surface to lose its original shape.
a) metal to metal
b) corrosion
c) compression
d) oxidation
c) compression
_________ refers to cracking or splitting wear caused by exposing metal parts to temperature extremes such as rapid heating and cooling cycles.
a) metal to metal
b) corrosion
c) thermal shock
d) oxidation
c) thermal shock
Thermal shock chambers that are used to test materials are capable of taking product from 200°C to -75°C (392°F to -103°F) and back in ten seconds or less.
What is the AWS specification # for;
Surfacing Electrodes for Shielded Metal Arc Welding
a) A5. 12
b) A5 . 13
c) A6. 12
d) A6. 13
b) A5 . 13
Surfacing Electrodes for Shielded Metal Arc Welding
AWS specification A5.13.
E Co Cr - A
What does the E indicate
E - SMAW Electrode
Co Cr - Chromium Carbide Alloy containing Cobalt & Chromium
A - Electrode is part of a basic group
AWS specification A5.21.
R WC2-20/30
What does the R indicate
R - welding rod
WC - (W = tungsten) (C=carbide)
2 - Chemical composition of the tungsten carbide granules
20/30 - indicates the mesh size of the tungsten carbide granules
AWS specification A5.23.
F7A3-EC NI1-NI2
What does the F indicate
Submerged arc welding unit
What metal has the following characteristics
- It is the hardest and most abrasion-resistant of all hard surfacing filler metals.
- widely used on oil well rock drill bits and screw conveyors
- It is best suited for resistance to abrasion.
- It is not recommended for protecting both surfaces in sliding contact.
a) martensitic stainless steel
b) chromium carbide
c) tungsten carbide
d) semi austenitic steels
c) tungsten carbide
What metal has the following characteristics:
- It is extremely resistant to wear and abrasion.
- It is used for earth cutting tools, conveyor systems used to transport ore and other abrasive materials and for steel mill tong tips.
- It is slightly superior to tungsten carbide for impact resistance.
a) martensitic stainless steel
b) chromium carbide
c) tungsten carbide
d) semi austenitic steels
b) chromium carbide
What metal has the following characteristics:
- used for metal-to-metal wear
- deposits should be at least two layers thick
a) martensitic stainless steel
b) chromium carbide
c) tungsten carbide
d) semi austenitic steels
a) martensitic stainless steel
What metal has the following characteristics:
- good wear resistance and good impact resistance.
- probably the most widely used.
- work well in earth-to-metal abrasion wear service
a) martensitic stainless steel
b) chromium carbide
c) tungsten carbide
d) semi austenitic steels
d) semi austenitic steels
________ steels have the following characteristics.
* They are good alloys for resistance to impact.
* They are used for roll crushers, hammers for mineral processing and railway track components.
* The deposit is work-hardenable and contains 11% to 14% manganese.
a) Austenitic Manganese Steels
b) Heat Treatable Steels
c) Copper Alloys
d) Austenitic SS
a) Austenitic Manganese Steels
_________ have the following characteristics.
* They are sometimes used as base layers for other hardfacing materials
eg. cladding inside tanks for corrosion resistance.
* They provide a tough ductile coating with good resistance to chipping and corrosion.
a) Austenitic Manganese Steels
b) Heat Treatable Steels
c) Copper Alloys
d) Austenitic SS
d) Austenitic SS
_______ have the following characteristics.
* They are high carbon steels, medium carbon alloy steels or tool and die steels.
* The deposit is hard if cooled quickly or soft and tough if cooled slowly.
* They are used for coal handling equipment and agricultural equipment subject to any soil conditions.
a) Austenitic Manganese Steels
b) Heat Treatable Steels
c) Copper Alloys
d) Austenitic SS
b) Heat Treatable Steels
________ have the following characteristics.
* They are used for sliding metal-to-metal contact.
* Most have good salt water corrosion resistance.
* They are used on bearing surfaces and ship propellers.
a) Austenitic Manganese Steels
b) Heat Treatable Steels
c) Copper Alloys
d) Austenitic SS
c) Copper Alloys
RPE is important when __________. Welding fumes are formed when hot metal vapours cool and condense into very small particles. Welding smoke is an example of a visible fume.
a) metal to metal
b) hard facing
c) thermal shock
d) oxidation
b) hard facing
Fumes such as those produced during the welding of _______ may produce serious, long-lasting problems. These can include chronic breathing difficulty and, in the case of exposure to chromium, cancer.
a) high carbon steel
b) nickel
c) copper
d) stainless steels
d) stainless steels
The common ______ problems are:
- dilution
- spalling
- underbead cracking
- stress failure
- distortion
a) metal to metal
b) hard facing
c) thermal shock
d) oxidation
b) hard facing
_______ is the mixing of the base metal with the hardfacing filler metal. The deep penetration characteristics of some arc welding processes can result in excessive ______ of the weld metal with the base metal.
a) dilution
b) hard facing
c) thermal shock
d) oxidation
a) dilution
If there is too much dilution, then the desirable characteristics of the hardfacing material are watered down by the ______ base metal.
a) harder
b) softer
b) softer
These guidelines help avoid excessive ________
- use low current settings
- use slower rate of travel
- use correct polarity
- use of flat or horizontal produces min _______
a) dilution
b) hard facing
c) thermal shock
d) oxidation
a) dilution
Increasing the overlap between beads reduces _____
a) dilution
b) hard facing
c) thermal shock
d) oxidation
a) dilution
Stringer beads generally produce the ______ dilution.
a) least
b) most
b) most
______ occurs when the weld metal breaks away from the base metal
a) dilution
b) spalling
c) thermal shock
d) oxidation
b) spalling
______ can be avoided with the following procedures.
- Prepare the surface. A good bond can be obtained only when the surface is perfectly clean and smooth.
- Control the cooling rate. If the cooling rate is too fast, brittle areas may occur in the base metal.
- limit the deposit thickness
a) spalling
b) dilution
c) thermal shock
d) oxidation
a) spalling
What process does this describe
- If a thicker deposit is necessary, build up the object with a filler metal that matches the chemistry of the base metal before hard surfacing
The stainless steel bonds well with the base metal and the hardfacing metal. This prevents ______.
a) spalling
b) dilution
c) thermal shock
d) oxidation
a) spalling
_________ can be avoided with the following procedures
- Cool the part slowly and evenly in a furnace or cover it with insulating material.
- preheat slowly and uniformly
- avoid interruptions during welding
a) spalling
b) dilution
c) thermal shock
d) stress failure
d) stress failure
_______ cracking occurs in the base metal just under the weld.
a) throat
b) surface
c) underbead
d) root bead
c) underbead
The cracks may not be visible on the surface, but they can lead to more serious defects such as spalling or weld cracking.
_______ cracking can be avoided with the following procedures.
* Make sure the part is at a temperature of
21°C - 38°C (70°F - 100°F) before beginning the hardfacing procedure.
* Be sure to preheat the base metal to specified preheat temps
a) throat
b) surface
c) underbead
d) root bead
c) underbead
______ occurs when unbalanced stresses are created during uneven expansion and contraction.
a) spalling
b) distortion
c) thermal shock
d) stress failure
b) distortion
The following methods are used to reduce ______
* Allow _____ forces to work positively.
Preset flat, thin or simple shaped parts by bending, forming or clamping prior to the welding process.
* dont overheat the part - use low current settings - weld in two separate areas
* relieve internal stresses
* Preheat the entire part slowly and evenly before welding and then peen each layer during cooling.
Allow the part to cool as slowly as possible.
a) spalling
b) stress failure
c) thermal shock
d) distortion
d) distortion
True or False
The following procedural considerations are necessary to produce the desired characteristics in the weld deposit:
* surface preparations
* buildup
* electrode selection
* cooling rate
* preheat,
* hardfacing patterns.
True
Hardfacing material that is very high in _____ and _____ has a tendency to crack on the surface as it cools, even when following manufactures specified welding procedures.
a) chromium
b) tungsten
c) nickel
d) both a & b
d) both a & b
Image shows cracks that have formed in a chromium carbide _____ weld after cooling. These cracks are considered normal and not a risk to create a notch effect as they are on the external surface only.
a) spalling
b) dilution
c) thermal shock
d) hard facing
d) hard facing
Before hardfacing is applied, a badly worn surface should be _____ with an electrode similar to the base metal.
a) surface prep
b) cooling rate
c) preheating
d) buildup
d) builtup
The _____ has a significant impact on the control of undesirable hardfacing side effects.
a) surface prep
b) cooling rate
c) preheating
d) buildup
b) cooling rate
Methods you can use to control the _______.
- preheat the materials
- maintain the correct interpass temp
- insulating the surface with dry sand, lime or fireproof blanket
a) surface prep
b) cooling rate
c) preheating
d) buildup
b) cooling rate
Hard facing _____ pattern works well for earth moving equipment.
a) zig zag
b) stringer beads
c) waffle
d) dot pattern
c) waffle
The ____ pattern works well on base metals that should not be overheated during welding
a) zig zag
b) stringer beads
c) waffle
d) dot pattern
d) dot pattern
Where larger pieces of ore, rock or slag are being handled, ______ are applied parallel to the flow of material to act as runners.
a) zig zag
b) stringer beads
c) waffle
d) dot pattern
b) stringer beads
Austenitic manganese steels are used in areas that require resistance to: (20)
impact
distortion
thermal expansion
corrosion or thermal cracking
impact
A squeezing type of wear that is caused by a heavy static load or pressure on a metal surface is known as: (15)
impact
abrasion
corrosion
compression
compression
What procedure can be done to prevent cracks from forming after hardfacing with chromium carbide filler metals? (27)
a) anneal the surface prior to welding
b) pre-heat and post weld heat treatment required
c) no prevention is necessary, it is a normal occurrence
d) weld a layer of less hard material over the hardfaced surface
c) no prevention is necessary, it is a normal occurrence
Which of the following is a procedural consideration when applying hardfacing materials: (26)
amount of buildup
surface preparation
cooling rate
all of the above
all of the above
A gouging type of wear that washes away or grooves out the metal surface is called: (13)
erosion
oxidation
corrosion
abrasion
erosion
A cracking, splitting type of wear caused by exposing metal parts to rapid heating and cooling cycles is called: (16)
thermal shock
erosion
abrasion
impact
thermal shock
Which answer defines the breaking away of the weld metal from the base material? (23)
spelling
spalling
corrosion
oxidation
spalling
What advantage does chromium carbide filler metal provide over other filler metal characteristics? (19)
a) it provides excellent resistance to spalling
b) it is used to weld on rock drill bits
c) it is used for metal to metal wear
d) it is extremely resistant to abrasion
d) it is extremely resistant to abrasion
GMAW surfacing applications utilize: (6)
a) pulsed DC current
b) electrodes with alloying elements in the core wire
c) a hopper system with tungsten powder than can be added to the weld puddle
d) all of the above
d) all of the above
Sugaring can be caused from welding on stainless steel, and it could be referred to as: (15)
corrosion
erosion
abrasion
oxidation
oxidation
What procedure is used to avoid excessive dilution when hardsurfacing? (22)
a) use low current settings
b) use high current settings
c) use an increased rate of travel
d) vertical uphill welding is recommended
a) use low current settings
Hardfacing may be applied on: (2)
new parts
worn parts
stainless steel
all of the above
all of the above
A sliding scraping type of wear that removes metal by gouging or grinding is called: (12)
impact
erosion
corrosion
abrasion
abrasion
Spalling may be reduced with the simple procedure of cleaning the welding surface from contaminants. (23)
True / False
True
Distortion can be caused by: (25)
a) slow cooling
b) pre-setting the weldment
c) even expansion and contraction
d) uneven expansion and contraction
d) uneven expansion and contraction
Which of the following AWS specifications would apply to SMAW electrodes for hardfacing? (17)
A 5.1
A 5.3
A 5.7
A 5.13
A 5.13
Which method could control the cooling rate of a hardfacing weldment and reduce undesirable side effects? (28)
a) preheating the material
b) insulating with dry sand
c) maintain correct interpass temperature
d) all of the above
d) all of the above
Stress failure may be prevented by: (24)
a) quenching
b) controlled cooling
c) welding intermittently to reduce heat input
d) all of the above
b) controlled cooling
Shielded metal arc surfacing electrodes are available for AC or DC welding current: (9)
True / False
True
A special form of corrosion resulting in the crumbling or flaking off of a metal is called: (15)
erosion
oxidation
compression
thermal shock
oxidation
Dilution would be more likely to happen during which hardfacing process? (8)
OAW
SAW
SMAW
GMAW
SAW
To avoid underbead cracking when hardfacing, the minimum temperature of the base material should be: (25)
a) 21 degrees-38 degrees C, (70 degrees-100 degrees F)
b) 30 degrees-50 degrees C, (85 degrees-122 degrees F)
c) 42 degrees-64 degrees C, (108 degrees-147 degrees F)
d) 50 degrees-75 degrees C, (86 degrees-167 degrees F)
a) 21 degrees-38 degrees C, (70 degrees-100 degrees F)
The advantage to using the oxy-acetylene process for hard surfacing is: (10)
a) base metal dilution is reduced compared to other methods
b) high deposition rates are superior to other processes c) it is a quicker way of applying surfacing material
d) it is suited best for the waffle pattern of surfacing
a) base metal dilution is reduced compared to other methods
Hardfacing can be applied by using materials in the form of: (5)
paste
liquid
filled tubes
all of the above
filled tubes
The purpose of hardfacing is to: (2)
reduce downtime costs
prolong life of parts
combat wear
all of the above
all of the above
Thermal spray surfacing is a process that? (11)
a) requires the GMAW spray mode of metal transfer
b) is performed underwater to reduce fumes
c) requires the correct distance and heat for success
d) is applied with iron powder particles
c) requires the correct distance and heat for success
Exposure to chromium fumes encountered with hardfacing could cause cancer. (21)
True / False
True
Which hardfacing alloy is used to resist metal to metal wear? (19)
copper alloys
tungsten alloys
chromium alloys
all of the above
copper alloys
The type of wear that pits, perforates, and eventually dissolves metal is called: (14)
erosion
abrasion
corrosion
thermal shock
corrosion
Stringer beads produce more dilution than weave beads when applying hardfacing. (23)
True / False
True
