Carbon And Alloy Steels Flashcards
Chain, nails, rivets, pipe, screw, wire (which carbon class, low, med…)
Low
Bar stock, plate, structural shapes
(Which carbon class low, med..)
Mild steel (0.15 - 0.30)
Axles, connecting rods, shafting
(Which carbon class low, med..)
Medium
Crankshafts, scraper blades, automotive springs, anvils, band saw blades (which carbon class low, med…)
High
Chisel, punches, hand tools, dies, metal cutting saws, files, reamers… (which carbon class low, med…)
Very high
Structural steel plate and shapes
CSA and ASTM
Steel sheet stock
AISI
Steel bar stock
SAE and AISI
What is the main purpose of adding chromium to steel
Corrosion resistance
Which element provides the best resistance to creep
Molybdenum
Which element is best for low temperature service applications
Nickel
At what carbon content does preheat become important when welding steel at room temperature
Medium carbon
CSA system, 300W means …
300 represents the tensile strength in MPa
W represents the type of steel (W means weldable)
SAE and AISI 4 digit designation system meanings …
1: major class
2: subclass
3 &4: approx carbon content
ASTM system what does the A stand for
Ferrous
The P - numbers in the ASME system are for ..
Similar chemical composition
Mechanical properties and weld ability
Help with weld procedures
ASME used same system as ASTM but adds an “S” in front of the “A”
Codes and admin for ASME and CSA
CWB and ABSA
What does the suffix QT represent in the CSA steel classification system
Quenched and notch tough
What do the last two numbers mean in the SAE designation 1030?
Carbon content in the 0.01%
Increasing hardness will sharply ….
Decrease ductility
Preheat only necessary if steel is thick or cold
Low carbon
Difficult to weld
Preheat and temperature control may be necessary
Medium carbon steel
Poor weldability
Preheat, post heat and interphase temperature control critical
High carbon steel
Hardly ever welded
Replacements are most likely necessary
Keep penetration as low as possible and use slow travel speeds
First pass will have the highest risk of cracking
Very high carbon
Principal hardening agent
(Element)
Carbon
Combines with sulphur to offset brittleness
(Element)
Manganese
Improves oxidation resistance
Silicon
Improves machining quality’s (0.1 to 0.15%)
Sulphur
Improves atmospheric corrosion resisting properties
Copper
Improves strength, corrosion resistance and machinability
Phosphorus
Refines grain structure during heat treatment increases toughness and hardenability
Vanadium
Small additions of alloying elements from 2% to just below stainless steel.
Add chemical and mechanical properties.
Better strength to weight ratio than plain carbon steel.
Low alloy steel
Low carbon steel (less than .20% carbon)
Less than 2 % total allot content
Increase mechanical properties
Better strength to weight ratio
High strength low alloy
E8018-B smaw electrode is…
A low alloy steel welding rod
Alloys will be at least 80,000 psi and have a letter suffix at the end
B represents chromium molybdenum as an addition
AWS E8018-B2
E- electrode
80 - tensile strength 80,000 psi minimum as welded
1 - all position
8 - lime coated low hydrogen deposit
B2 - chemical composition of the deposited weld metal
8018 suffixes
A, B, C, D, G, M, NM
A - carbon molybdenum
B - chromium molybdenum
C - nickel
D - manganese molybdenum
G - general
M - military
NM - nickel molybdenum
Who are the two organizations that designate filler materials
CSA and AWS
Any SAE designation number that the first digit is greater than one means
It’s an alloy steel
Red hardness
Ability to maintain shape while hot
Tungsten
Aluminum is used for what purpose when added to steel
Deoxidizer
Makes steel stronger
Corrosion resistant
High temp service
Stainless min 10 %
Increase strength
Chromium
Second most imp metal in stainless
Good at hot and cold temp
Tensile strength 6,000 psi for each 1 % of …
Nickel
Increase hardness
Endurance
Creep (the slow stretching of a steel under stress at high temp)
Molybdenum
Alloy in steel always present and helps with machining
Sulpher
High strength
High heat resistance
Cobalt
B pressure test
6” diameter
Sched 80 carbon steel pipe
P1 material group
In high percentages this element is considered an impurity. Low percentage up to 0.01 % slightly improved strength and corrosion resistance of low carbon steel
Phosphorus
In the AWS classification system for low alloy electrodes what identifies the specific additions for alloys
The suffixes
Which governing body writes specifications for structural steel shapes and plates
ASTM
American society for testing materials
4 common types of low alloy steels
Nickel
Chromium
Nickel chromium
Molybdenum
The content of this element in carbon steel is usually below 0.05 % but a content of 0.1% to 0.15% can improve machinability
Sulphur
What is indicated by the first digit in the SAE or AISI numbering system
Class of steel
Steel does not require pre heat at room temp, excellent weldability
Low carbon
The slag of an E10018 is similar to the slag of which electrode
E7018
Oxidation resistant
Prevents atmospheric corrosion
Reduces hot shortness (not be brittle)
Silicon
Meant to offset hot shortening (brittle at high temp)
Manganese
Pressure vessels uses the p number system
ASME
Titanium
Deoxidizer
CSA type A material states that the material
Atmospheric corrosion resistant weldable steel
CSA type G material states that the material
General construction steel
Why is it important to let weld cool slowly when welding on med high carbon steel
Hydrogen induced cracking is possible
If you have to weld very high carbon steel where is the weld going to be most susceptible to cracking
First pass and heat affected zone beside the weld
What is the main element in carbon steel
95 % iron
