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58 Cards in this Set
- Front
- Back
the discovery of stainless Steel dates back to when?
|
1900's
120301 pg 2 |
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stainless steels are what alloys?
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iron-chromium alloy
120301a pg 2 |
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most stainless steels have a low carbon content range of what?
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0.03% to 0.10%
120301a pg 2 |
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stainless steels require what minimum percentage of chromium?
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10%
120301a pg 2 |
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chromium in stainless steels does what?
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forms the corrosion resistant oxide layer and increases resistance to creep
120301a pg 3 |
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sinless steels have what properties?
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improves corrosion resistance and increases resistance to oxidation
120301a pg 3 |
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nickel in excess of 6% in stainless steel increase what?
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corrosion resistance
120301a pg 3 |
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what is sometimes used as a lower cost replacement for nickel?
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maganese
120301a pg 3 |
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what two things does molybdenum do in stainless steel?
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increased resistance to pitting type corrosion
-improves high temperature strength 120301a pg 3 |
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stainless steel filler metal should what?
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match or exceed the chemistry of the parent metal
120301a pg 4 |
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what is the most common grade of stainless steel?
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austenitic stainless steels
120301a pg 5 |
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are austenitic S.S. magnetic or non-magnetic?
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non-magnetic
120301a pg 5 |
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what stainless steel keeps its microstructure during and after cooling from elevated temperatures?
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austenitic stainless steel
120301a pg 5 |
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In 304N what does the N denote?
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an addition of nitrogen
120301a pg 5 |
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In 316H what does H stand for?
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high carbon
120301a pg 5 |
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how is low carbon content indicated on a rod?
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with an L suffix
120301a pg 5 |
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what do nitrogen rods increase in stainless steel?
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strength of the steel and stability of the austenite
120301a pg 5 |
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what does a high carbon content rods affect the stainless steel?
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increase high temperature strength
120301a pg 5 |
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what are low carbon used to help eliminate?
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carbide precipitation
120301a pg 5 |
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why does austenitic stainless steel keep its Face-centred structure at all temperatures?
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because of the amount of nickel in it
120301a pg 6 |
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can you heat treatment austenitic stainless steel?
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no
120301a pg 6 |
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what stainless steels are considered straight chromes?
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ferritic and martenistic
120301a pg 7 |
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low chromium alloy(apron. 11%) ferritics Stainless Steel's are used extensively where?
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automotive exhaust systems
120301a pg 7 |
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martensitic stainless steels generally require what when welding?
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preheat and postheat
120301a pg 8 |
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what is the advantage of duplex stainless steels over austenitic stainless steels?
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resistance to stress corrosion cracking and pitting and yield strengths that are twice that of the austenitic alloys
120301a pg 9 |
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precipitation hardening stainless steels have what ability?
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the ability to develop high strength with reasonably simple heat treatments
120301a pg 9 |
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what series of stainless steel has the highest tonnage?
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200 and 300 series
120301a pg 10 |
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increasing the silicon content in austenitic stainless steels improves what?
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heat resistance
120301a pg 10 |
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What does the B denote in 302B?
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the addition of silicon
120301a pg 10 |
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Are 400 series ferritic and martensitic stainless steels magnetic?
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yes
120301a pg 11 |
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what series of SS are not classes as stainless steels?
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500 series
120301a pg 12 |
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carbide precipitation is also known as what?
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weld decay
120301a pg 13 |
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at what temperature range does carbide precipitation occur?
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427°C-816°C(800°F-1500°F)
120301a pg 13 |
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where does carbide precipitation occur?
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the heat affected zone
120301a pg 13 |
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what is the maximum carbon content in stainless steels with extra low carbon (ELC) and low carbon (L)?
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0.03%
120301a pg 14 |
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what stabilizer can you use to prevent carbide precipitation?
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-columbium(niobium)
-titanium -tantalum 120301a pg 15 |
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steels in which chromium carbide forms readily upon heating to the sensitizing temperature range are called what?
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unstabilized steels
120301a pg 15 |
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how does rapid quenching prevent carbide precipitation?
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the rapid quench prevents carbides from reforming
120301a pg 15 |
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can you use small diameter electrodes and low amperage settings to prevent carbide precipitation?
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yes
120301a pg 16 |
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what should your interpass temperatures not exceed when welding stainless steel?
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316°C(600°F)
120301a pg 16 |
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what stainless steel rod is used for welding mild steel to stainless steel?
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E309
120301a pg 19 |
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what coating and polarity is as E308L-15 electrode?
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-lime coating
-DCRP(electrode positive) 120301a pg 20 |
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what is the coating and polarity for a E309L-16 electrode?
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-titania type coating
-AC or DCRP(electrode positive) 120301a pg 20 |
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what is added to the flux of a E309L-16 to allow it to run on AC?
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potassium
120301a pg 20 |
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stainless steel consumable inserts are shown how?
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the prefix IN is added (IN 308 L)
120301a pg 24 |
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when are stainless steel flux cored GTAW welding rods used?
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where back purging is not possible and when slag removal is not a concern
120301a pg 24 |
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all stainless steel electrodes have what type of coating?
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lime or titania
120301a pg 25 |
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how long can you normally store hermetically sealed electrodes for without them deteriorating?
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several months
120301a pg 25 |
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what temperature is your oven for storing your stainless steel rods?
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93°C-121°C(200°F-250°F)
120301a pg 26 |
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rebaking stainless steel rods takes how long and and at what temperature to retire them to their original condition?
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-one hour
-260°C(500°F) 120301a pg 26 |
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why do you have to be carful when using rods that have been rebaked?
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the coating may fall off the core wire
120301a pg 26 |
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who should you consult to find out how many times you can rebake an electrode?
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the manufacturer
120301a pg 26 |
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why should you store stainless steel on wood away from carbon steels ?
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so it does not get contaminated
120301a pg 27 |
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chlorine and fluorine contribute to what in stainless steels?
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stress corrosion and cracking
120301a pg 28 |
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current range for austenitic stainless steel covered electrode are what percentage lower for the same size of carbon steel SMAW electrode?
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10%-15%
120301a pg 29 |
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In a surfacing operation on carbon steel you doposit the first layer with E309 and subsequent layers with E308 why?
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to ensure martensite does not form in the first layer
120301a pg 30 |
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are ferritic stainless steels able to be hardened by heat treatment?
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No
120301a pg 31 |
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what are the most common astenitic stainless steel SMAW electrode used for welding ferritic stainless steels?
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E309 and E309L
120301a pg 32 |