WEL 400

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Using the last two numbers of the SAE system, what would 1018 represent?

.18% C

The range of carbon in medium carbon steels is:

0.3% - 0.5%C

With a 4340 steel, there will be what % of carbon?

0.40%

What is maximum permissible limit of Si in carbon steels?

0.60%

This series is generally utilized in filler metal form.

4000

If a weldment made from 1" 6061T-6 needs to respond to heat treatment, the best filler metal selection would be:

4643

The 4 in E7018-H4R represents:

4ml of diffusible hydrogen per 100 grams of weld

When a 6061 is welded with a dissimilar filler, the composition of the admixture should be:

50% 4043 70% 5356

This aluminum alloy has good weldability, is non-heat treatable and is primarily used for structural applications.

5000

Which of the following aluminum alloys would be considered non heat-treatable?

5000

If a 6061 alloy is going to be anodized, which filler would provide the best color match?

5356 5556

How much does the volume of material decrease when an Al changes state from a liquid to a solid?

6%

Due to the potential of creating alpha case, the percentage of Al contained in Ti is kept at:

6-8%

Due to the potential of creating brittle phases, the percentage of Al contained in Ti is kept at:

6-8%

This aluminum alloys series would be considered the most versatile of the heat treatable alloys.

6000

This aluminum series should never be autogenously welded.

6000

Which of the following aluminum alloys would be considered heat-treatable?

6000

This type of aluminum alloy series can be heat treated to close to 100,000psi.

7000

Ti must be shielded until it reaches below this temperature, otherwise the oxide layer will grow too thick, and contamination of the weld zone will have occured.

800F

When exposed to temperatures above , unshielded Ti can pick up oxygen, nitrogen, carbon, and hydrogen.

800F

This heat treatment process will precipitate fine alpha particles from the unstable beta phase produced by solution treatment

Aging

This heat treatment process will precipitate fine alpha particles from the unstable beta phase produced by solution treatment.

Aging

The main alloying element in the 1000 series is:

Al

This element has the second most pronounced effect on the interstitial strengthening of unalloyed Ti.

Al

A stainless steel is said to be stabilized if there are alloys added to it to react with the oxygen before the chromium does.

False

As carbon content increases below the eutectoid point, it is harder (requires more temperature) to create austenite.

False

As long as the oxide layer color is acceptable, the weld is deemed 100% acceptable.

False

Because of the austenite stabilization in dss and sdss steels, they can be used at cryogenic temps.

False

Because of their high thermal conductivity, stainless steels are able to avoid distortion quite readily.

False

Chromium is a more effective at stabilizing ferrite, than nickel is at stabilizing austenite.

False

Diluted weld metal will have a lower FN than undiliuted because the ferrite level of the base metal is purposely kept high and unbalanced.

False

Distortion is a major concern when welding Ti due to the low thermal conductivity and high coefficient of thermal expansion.

False

FN and %ferrite are essentially the same. That means if you have an FN of 45, you have about 45% ferrite in the material.

False

Generally speaking, ferritic steels are usually susceptible to solidification cracking because the ferritic phase is so brittle.

False

HSLA steels always require a PWHT.

False

HSLA steels are generally classified by their chemical compositions, as opposed to their mechanical properties.

False

HSLA steels are known to have more carbon than mild carbon steels.

False

If a high carbon steel is welded with a nickel based electrode, the weld will have the same hardness values as the base material.

False

In order to ensure complete color match, a material that is to be anodized should be welded with a 4xxx series filler material.

False

It is a good idea to use the Schaeffler and DeLong diagrams to predict the FN number of sdss and dss.

False

It is possible to accurately (with all confidence) predict the FN of a weld.

False

Martensite is an iron-carbide with zero tensile ductility.

False

Martensitic stainless steels should be used when you need excellent corrosion resistance and high strength, as compared to the other stainless steel types.

False

Once created, it is impossible to dissolve chromium carbides in the material.

False

Q&T steels are sometimes furnished in the as rolled condition.

False

Q&T steels rely on upper bainite, ferrite, and pearlite to get their elevated strengths.

False

Sensitization occurs when chromium gets tied up with another element other than carbon.

False

Since there are no commercially available filler materials, it is advisable to weld 6xxx base material autogenously.

False

Stainless steels are able to efficiently transfer electricity.

False

Stainless steels have a lower coefficient of thermal expansion as compared to carbon steel.

False

The 4xxx filler material should be stored in a controlled-environment cabinet when not in use because it is so susceptible to developing a hydrated surface.

False

The FCC structure is particularly susceptible to cracking if there are impurities present.

False

The FN number is determined by image analsis or point grid measurements, while the %F is a measurement of the magnetism of the material.

False

The ability of the passive layer to repair itself is contingent upon there being both Cr and Ni available.

False

The biggest challenge when welding ferritic stainless steels is grain growth in the HAZ, so you should be sure to preheat the material to prevent this.

False

The dss and sdss filler materials are usually over-alloyed with Cr in order to promote the ferrite phase upon cooling.

False

The effect of carbon on the A3 line is negligable.

False

The martensite phase will have the highest level of hydrogen embrittlement potential, but a bainitic structure will not be at risk at all.

False

The only 7xxx series base materials that are weldable are those with higher Cu values.

False

The strengthening effect from heat treatmnet in beta alloys occurs as a result of an increase in the beta grain size.

False

The thicker the material, the higher the tensile strength per square inch. This is known as the Effect of Mass.

False

There is no need to preheat aluminum because hydrogen isn't very soluble in aluminum.

False

Ti does not experience grain coarsening.

False

Usually Q&T steels are welded in the as-rolled condition.

False

Vanadium determines the maximum hardness that a steel can achieve.

False

Weld metal is generally less susceptible to hydrogen embrittlement due to it containing a higher amount of carbon.

False

This process is considered to be the lowest low hydrogen process:

GTAW

At 1700oF and above, ferritic stainless steels experience:

Grain Growth

The microstructure of the Ti alpha phase is:

HCP

What type of steel is generally classified by its mechanical properties, as opposed to its chemical composition?

HSLA

If you add this gas to your shielding gas mix when welding aluminum, it will increase your penetration due to the increase in ionization energy.

He

You can increase the temperature of the GMAW arc by adding this high ionization potential gas, which should allow the weld to stay fluid long enough to prevent trapping of porosity when welding aluminum.

He

An austenitic stainless steel may have elements added to it to prevent loss of ductility and loss of corrosion resistance at elevated temps. An example of such an element would be:

Tantalum Niobium Titanium

This color is generally widely accepted as being the limit for oxide layer thickness when visually inspecting welds in Ti:

Strae

If an aluminum classification has an H suffix, what does that tell you about the material?

Strain Hardened

This type of stainless steel would be high in levels of Cr and extremely low in the levels of interstitial elements:

Super Ferritic

This temper is a product of a solution heat treatment and natural ageing.

T4

This temper is a product of a solution heat treatment and artificial aging:

T6

If an aluminum classification has an T suffix, what does that tell you about the material?

Tempered

Q&T steels rely on the transformation products of:

Tempered martensite and lower bainite

The difference between CP1 - CP4 is:

The amount of O2 and Fe

A Q&T steel will always require a PWHT.

False

A rimmed steel is completely deoxidized during the steel making process.

False

Shielding gas purity is very important when welding Ti, and the dew point measurement of the gas indicates how pure the shielding gas is. Most Ar shielding is provided at this level:

-60F

After welding on an alloy with a -T6 temper, with no PWHT it can only attain a temper.

-T4

At what carbon level do we generally consider the steel to be unweldable?

1.0%

What is the maximum permissible limit of Mn in carbon steels?

1.65%

Generally speaking, in order to be a stainless steel, there should be at least what percentage of Cr?

10.5-12%

This aluminum series would be used when thermal/electrical conductivity or corrosion resistance are paramount.

1000

This is the generally accepted minimum amount of Cr necessary in order for a material to be considered a stainless steel:

11%

At what point might the material thickness of a heat treatable aluminum be too thick to provide enough dilution for the weld metal to respond to heat treatment?

12.5mm

Generally speaking, what is the threshold temperature for Ti in a service application due to the excessive growth of the oxide layer?

1200F

This is the melting point of pure aluminum:

1200F

If a preheat is absolutely necessary, you should keep the temp below:

200F

This aluminum alloy is great for general purpose, and displays moderate strength with good workability. It is often used in the beverage industry.

3000

For the welding of dissimilar metals (eg. CS to SS), which filler metal would you recommend?

309L

Generally speaking, this filler metal classification would contian higher levels of alloying elements as compared to the other fillers that are listed.

316L 309/309L

This is the melting point of the aluminum oxide:

3700F

When welding Ti, the material must be shielded until it reaches below this temperature, otherwise it can dissolve discreet amounts of atmosphere into the solid base material.

800F

In this temperature range austenitic stainless steels may experience intergranular corrosion due to the creation of chromium-rich carbides forming at the austenitic grain boundaries.

840F to 1550F

This is the melting range of alloyed aluminum:

900F - 1200F

Generally speaking, SDSS have a PRE of:

>40

A nonheat-treatable weldment will experience a more ductile HAZ because:

A full anneal occcurs in the HAZ and the stress from cold-working will be lost due to recrystallization

The "L" in 309L is representative of:

A low level of C

Steel's fairly unique ability to transfrom between phases and exhibit multiple phases is known as:

Allotropic

If an aluminum alloy is non-heat treatable, the only increase in strength will be as a result of:

Alloying elements Cold working (strain hardening)

As a group, this Ti alloy generally has the highest creep strength.

Alpha

Considering all the types of Ti available, which would be the most susceptible to hydrogen embrittlement?

Alpha

This phase of Ti is particularly susceptible to contamination cracking because of its microstructure and how it is affected by interstitial elements.

Alpha

This category of Ti would most likely be used for cryogenic applciations

Alpha and Near Alpha

When using a hardness measurement to predict tensile, this could throw the results off:

Alpha case

This category of Ti is known for outstanding strength-to-weight ratios in the heat treated condition:

Alpha-Beta

This element is most widely used as a substitutional strengthener and alpha stabilizer for Ti due to its cost and availibility.

Aluminum

The factors that would best describe an increase in the likelihood of hydrogen embrittlement are:

Amount of Diffusible Hydrogen, Harder Microstructures, Tensile Stress

The factors that would best describe an increase the likelihood of hydrogen embrittlement are:

Amount of Diffusible Hydrogen, Harder Microstructures, Tensile Stress

Duplex stainless steels are known to be , which means they will exhibit different mechanical properties depending upon which way the grains are oriented.

Anisotropic

If an aluminum classification has an O suffix, what does that tell you about the material?

Annealed

If an austentic stainless is cold-worked, an increase in ferromagnetism can be remedied by:

Annealing

If an austentic stainless is sensitized, a decrease in corrosion resistance can be remedied by:

Annealing

Taking a material to a supersaturated solid solution condition, quenching it, then re-heating it to a lower temperature would be representative of what type of thermal treatment?

Artificial Ageing Precipitation Hardening

If an aluminum classification has an F suffix, what does that tell you about the material?

As fabricated

Stress in a weld will tend to concentrate:

At the Toe At the Root At any Notches

Carbon will stabilize this phase:

Austenite

In order to create martensite, you must first have:

Austenite

Nickel will stabilize this phase:

Austenite

It is generally accepted that this PH steel is the most difficult to weld due to the creation of liquid films along the grain boundaries, and some of the alloying elements being lost to oxide creation.

Austenitic

Of the PH stainless steels, this grade can only be hardened through an ageing heat treatment.

Austenitic

When welding martensitic stainless steels, if you need ductility of the weld you should pick a filler made of:

Austenitic

Genearally speaking, duplex is primarily composed of these phases:

Austenitic / Ferritic

The ability of a stainless steel to regenerate the chromium oxide layer if it is removed is dependant upon:

Available Cr Available O2

Ferrite has a microstructure of:

BCC

The microstructure of the Ti beta phase is:

BCC

Martensite has a microstructure of:

BCT

When a 300 series is cold-worked, the FCC microstructure breaks down into a(n) structure, and may cause an increase in ferromagnetism.

BCT

Cr-Mo steels rely upon the microstructures of:

Bainite and martensite

Generally speaking, Ti will first solidify as this phase, then depending upon the level of alloying elements, it will allotropically change or remain metastable.

Beta

This phase of Ti is known to have the ability to dissolve higher amounts of H:

Beta

Which of the following Ti alloys would benefit the most from heat treatment?

Beta

Which phase of Ti has the highest amount of stabilizing elements?

Beta

This is the temperature in which Ti has an allotropic transformation, and when it occurs is dependent upon the alloying elements.

Beta Transus

Why would it be beneficial to have an FN number between 3 and 20 in austenitic weld metal?

Better resistance to cracking

If an HSLA requires a preheat, it will depend upon

Pcm Thickness of material Filler metal

This group of Ti would be utilized for corrosion resistance, but not usually for high strength.

CP

This formula allows us to predict and quantify the effect of the alloying elements in relation to the hardness they could produce or the liklihood of martensite formation.

Carbon Equivalent

What three things should be known in order to determine the weldability of a material?

Chemical, Mechanical, Thermal History

This alloy is a potent ferrite stabilizer, and is also added to improve strength at elevated temps and increase the materials resistance to corrosion.

Chromium

A PWHT on Cr-Mo material will be required if there is 2.25% Cr or less, and a low C filler metal is used.

False

The main alloying element in the 2000 series is:

Cu

The only way to refine the grain size of Ti is to:

Deformation processing and heat treatment

If an austenitic filler is chosen to weld martensitic stainless steels, you should first consider:

Differences in mechanical properties of the base metal and weld metal. Possible adverse effects of the pwht on the weld metal Environmental factors such as corrosion

Creep Resistance is defined by three characteristics of:

Elevated Temp, Pressure, Time

The alloy concentration where, when temperature increases, the material has a phase change from many microstructures to a single microstructure is known as:

Eutectoid Point

Generally speaking, 4xxx filler should not be used to weld 5xxx base materail because:

Excessive creation of magnesium silicide eutectics

The main alloying element in the 8000 series is:

Expiremental

Austenite has a microstructure of:

FCC

Before a BCT structure can be created, what structure must first be present?

FCC

This microstructure is much more accepting of carbon

FCC

What microstructure does Al exhibit?

FCC

When autogenously welding a carbon steel and you need some deoxidization to prevent porosity in the weld, you could select an E70s-2 to help clean the weld.

False

When autogenously welding a carbon steel and you need some deoxidization to prevent porosity in the weld, you could select an ER70S-2 to help clean the weld.

False

When iron atoms rearrange from ferrite to austenite there is a volumetric expansion. This is why carbon is more soluble in austenite than ferrite.

False

When welding high carbon steels, concave is better than convex.

False

This type of cracking is primarily a design issue, but can be increased by stress concentrations.

Fatique Cracking

Chromium will stabilize this phase:

Ferrite

Silicon will stabilize this phase:

Ferrite

Between the temperatures of 1341F and 1674F, the iron atoms may be arranged in what phase, depending on the carbon content?

Ferrite and Austenite

Below the temperature of 1341F, the iron atoms may be arranged in what phase, depending on the carbon content?

Ferrite and Pearlite

HSLA steels are strengthened by:

Ferrite grain refinement Precipitation hardening Substructural strengthening

This type of stainless steel has a coefficient of thermal expansion similar to carbon steels:

Ferritic

This type of stainless steel would be high in levels of Cr and lower in the levels of other alloys:

Ferritic

This type of stainless steel would have ferromagnetic properties

Ferritic Martensitic

Austenitic stainless steels may be prone to cracking. This may be partially due to:

High thermal expansion Low thermal conductivity Distortion stresses

An HSLA will require a PWHT under the following circumstances:

If it will be in a stress-corrosion cracking environment. Dimensional stability for machining

Sometimes there is an increase in the amount of C in a stainless steel filler metal. If so, it is added in order to:

Increase strength at elevated temps

The creation of chromium carbides promotes:

Intergranular corrosion

This type of cracking occurs as a result of a discontinuity in the material that occurred in the steel making process during the flattening of the material, and isn't usually noticed until after welding.

Lamellar Tear

To prevent excessive softening of the base metal in a high carbon steel, which of the following would not help?

Larger electrode

The "L" in 308L is representative of:

Low amounts of C

Hot cracking is a form of solidification cracking that results due to:

Low melting temp compounds (sulfur, lead, tin, etc.)

This phase is a feathery composition of ferrite and cementite?

Lower Bainite

Sometimes a 4047 series will prevent cracking better than a 4043. Why?

Lower melting range

In order to prevent iron sulfide inclusions, this element is added during the production of steel:

Manganese

This type of stainless steel can be heat hardened:

Martensitic

This type of stainless steel would be high in levels of Cr and C (relatively speaking).

Martensitic

Of the PH stainless steels, this grade can be hardened through martensite creation and an ageing heat treatment.

Martensitic Semi-Austenitic

PH stainless steels have strengths comparable to , but corrosion resistance comparable to .

Martensitic, Austenitic

This category of Ti is known for excellent formability, with high strength-to-weight ratios making them excellent for fasteners and springs.

Metastable Beta

The main alloying element in the 5000 series is:

Mg

The main alloying element in the 3000 series is:

Mn

This element has the most pronounced effect on the interstitial strengthening of unalloyed Ti.

N

Which of the following is an important alloying element in DSS and SDSS steels, but can be difficult to contain as it wants to escape at atmospheric pressure and below.

N

can be used as an effective and potent FCC stabilizer, but won't provide the same mechanical and physical properties that Ni provides.

N

This element is responsible for making the 300 series austenitic:

Ni

This element increases hardenability, is a strong austenite stabilizer and is resistant to the creation of oxides and carbides.

Nickel

The protective layer of stainless steel is said to be , which means that once it is created it does not react with anything else.

Passive

This formula allows us to predict and quantify the effect of the alloying elements in relation to the hardness they could produce or the liklihood of martensite formation in HSLA steels.

Pcm

High carbon steels can be successfully welded with:

Nickel filler Austenitic stainless filler Under-matched filler (dilution)

A preheat is necessary with this stainless steel to prevent hydrogen embrittlement :

None of the above

Between the temperatures of 1418F and 1675F iron exhibits this property:

Paramagnetic

This is the act of creating the protective layer in stainless steels:

Passivation

Generally speaking the goal is to keep carbon content low in filler materials to prevent opportunity for chromium-carbide creation, and is designated by an "L" suffix. When would an "H" suffix be utilized.

Possibly for high temperature applications

Generally speaking the goal is to keep carbon content low in filler materials to prevent opportunity for chromium-carbide creation, and is designated by an "L" suffix. When would an "H" suffix be utilized?

Possibly for high temperature applications

What element is frequently added to the flux coating in order to aid in arc stability?

Potassium

The AISI designation for steel is much like the SAE, with the exception of a:

Prefix that denotes which steel making process

What is the main difference between HSLA and Q&T steel?

Q&T is furnished in the heat treated condition

After a PH steel has been heated to create a homogeneous dispersal of the alloying elements, it must then be in order to lock those alloys in place.

Quenched

Which one of the following will not aid in preventing hardening of the base metal when welding high carbon steel?

Reduce rigidity of joint

This type of cracking occurs due to the HAZ grains being coarsened, and usually occurs during a PWHT.

Reheat Cracking

This diagram uses the chemistry of the material(s) to determine the resulting microstructure, and is usually used to determine the balance of ferrite and austenite.

Schaeffler Diagram DeLong Diagram WRC-1992 Diagram

Of the PH stainless steels, this grade is very complex and has an intermediate conditioning heat treatment to precipitate carbides in order to raise the Mf temp.

Semi-Austenitic

This term relates to the creation of chromium carbides:

Sensitization

If the 5XXX base material is high in Mg, care should be taken to ensure the 4XXX filler is low in , otherwise there will be a high propensity for cracking:

Si

The main alloying element in the 4000 series is:

Si

The main alloying element in the 6000 series is:

Si & Mg

This phase is a brittle phase that occurs in ferritic stainless steels when the temperature gets too high:

Sigma phase

This element promotes fluidity in the steel as a result of its low melting temp. It also acts as a deoxidizer.

Silicon

Which one of the following will not aid in preventing cracking of the weld metal when welding high carbon steel?

Slow travel speed

If a material is 6061-T6, then it has been:

Solution Heat Treated and Artificially Aged

In order for a PH steel to be hardened it must first be raised above the temperature in order to create a super-saturated solid solution.

Solvus

Some stainless steels can handle higher temperatures and delay the creation of chromium carbides due to the addition of certain reactive elements. These stainless steels are known as:

Stabilized

If you weld on a 6000 series aluminum with a 4000 series filler, the following is true:

The weld may respond to heat treatment depending upon the amount of dilution

In order to keep the FN number in balance when GMA welding, there may be an addition of N to the shielding gas.

True

Increasing the welding amperage and decreasing the travel speed may be an effective way to reduce the cooling rate for a welded material.

True

This is the most popular classification of Alpha-Beta Ti:

Ti-6Al-4V

A form of Ti used quite readily in the production of filler materials due to its refractive properties is:

TiO2 Rutile

This element is usually responsible for stabilizing stainless steels, and was very important before the advent of AOD.

Titanium

A higher solidification and cooling rate will produce a finer grained microstructure with greater strength and a decreased tendency for hot cracking.

True

Aluminum is able to increase in strength with no decrease in ductility with temps as low as -320F

True

An increase in % weight of Si or Mg will decrease the alloys crack sensitivity.

True

Austenitic stainless steel filler can be used on ferritic grade stainless, but can be cause for concern if the material is going to be placed in an SCC environment.

True

Austenitic stainless steels are usually limited in application over 1530oF due to heavy scaling issues.

True

Austenitic stainless steels have about a 50% greater thermal expansion as compared to carbon steels.

True

Austenitic stainless steels work well over a wide temperature range; from cyro temps to elevated service temps. They are able to do this because they don't have a sharp ductile-to-brittle transisiton like the other stainless steels.

True

Chromium is the main element responsible for the creation of the passive layer, in addition to oxygen.

True

Contamination is the most prevelant enabler of discontinuties in the welding of Ti.

True

Copper, titanium, niobium and aluminum are often used as precipitates in PH stainless steels.

True

Cracking as a result of hydrogen embrittlement can occur up to 48 hrs after fabrication.

True

Duplex stainless steels offer higher strength and better resistance to scc and pitting as compared to conventional stainless steels.

True

Filler metal selection for welding aluminum must be well thought out because while many fillers are acceptable, there is usually one selection that is most applicable.

True

First generation (430/434/442/446) ferritic stainless steels can produce a martensitic reaction upon cooling, so they will need to go through a pwht in order to dissolve any martensite and increase toughness.

True

Generally speaking, HSLA steels should require a low hydrogen welding process.

True

Generally speaking, for a material to be considered high alloy, it should have 8% or more of alloying elements.

True

Generally speaking, for a material to be considered low alloy it should have less than 4% of alloying elements.

True

Generally speaking, the only way to refine the grains of a ferritic stainless steel is by cold-working and then annealing because they generally can't transition to austenite through thermal treatment.

True

HTLA generally has a higher carbon content as compared to HSLA and Q&T.

True

Hardness testing is an acceptable way to predict the tensile strength of Ti.

True

Hydrogen is readily absorbed by liquid iron.

True

It is very difficult to avoid martensite formation in HTLA steels no matter how slowly you cool them down, and impossible to prevent martensite if there is no preheat.

True

Low hydrogen practices are the most cost effective and easily attainable ways to control hydrogen embrittlement.

True

Martensitic stainless steel are most successfully welded in the annealed condition, followed by a pwht to bring about some better toughness properties.

True

Martensitic stainless steel is considered heat hardenable.

True

Martensitic stainless steels are magnetic.

True

Martensitic stainless steels have the highest level of carbon relative to the other stainless steel types.

True

Nickel based stainless steels perform better in a reducing environment.

True

Oftentimes fabricators of superferritic stainless steels use a strip of the base material as filler metal as commercial filler material is often limited.

True

PH stainless steels are less susceptible to solidification and liquation cracking as compared to conventional austenitic stainless steels.

True

Passivation is the process of re-creating the chromium oxide layer.

True

Q&T steels are similiar in composition to HSLA steels, but they usually have a higher level of C, Cr, and Mo.

True

Si would be a good example of a ferrite stablizer in a filler metal.

True

Sigma Phase creation is generally only an issue when the Cr levels are above 13%.

True

Stabilizing BCC in an FCC structure could help eliminate hot cracking or solidification cracking.

True

The 400 series is a combination of ferritic and martensitic stainless steels.

True

The effect of carbon on the A1 line is negligable.

True

The eutectoid point is the alloy mixture that provides the lowest possible melting temp of the material.

True

The martensite phase will have the highest level of hydrogen embrittlement potential, but a bainitic structure would be susceptible as well, just at a lower level.

True

The preheat for HSLA steels may be dependent upon the selected filler material.

True

The stress as a result of a phase transformation could be enough to enable cracking from hydrogen embrittlement.

True

The use of Ti is generally limited to temperatures below 1200oF due to excessive oxide creation.

True

Ti has a comparable percent of elongation to carbon steels.

True

Titanium has a passive, tenacious, and self-renewing oxide layer just like stainless steels.

True

Titanium is unique in the fact that as temperature decreases it will experience an increase in tensile properties with little reduction of ductility.

True

Too little Mn in a steel can be harmful due to the incease in the likelihood of hot shortness, or a reduction of ductility at elevated temps.

True

Two materials could have the same identical chemistry, go through different thermal treatments, and have completely different mechanical properties.

True

Underbead cracking is the most common type of hydrogen induced embrittlement.

True

Using a filler metal of matching composition for the ferritic stainless steels can produce a weld and HAZ that lacks toughness.

True

With some high energy, low themal input welding processes, the creation of martensite may be a concern.

True

The main alloying element in the 9000 series is:

Unused

How can embrittled phases be prevented when fabricating superferritic stainless steels?

Water Quenching & Full Annealing

Hydrogen cracking can be problematic in Ti as it is in steels. However, the delay time for a hydrogen crack to occur in Ti can be up to:

Weeks to months

Generally speaking the goal is to keep carbon content low in filler materials to prevent opportunity for chromium-carbide creation, and is designated by an "L" suffix. When would an "N" suffix be utilized.

When more nitrogen is needed to increse the yield strength without impairing ductility .

Sometimes a small amount of a BCC structure can help a largely FCC structure, but sometimes is can't. Those times that it can't would be:

When there are elevated temps When there are cryo temps When ferromagnetism can't be tolerated

The main alloying element in the 7000 series is:

Zn

Cementite is:

an iron carbide

5xxx filler material will only be good for prolonged high temp service if it has 3.5% Mg and above.

false

A PWHT may not be necessary for an HTLA because we want the formation of the hard and brittle martensite.

false


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