Steel Flashcards
Beyond 2 % carbon in ferrous materials
Iron above steel below
2-4% carbon
Cast iron
4-4.5%
Pig iron
Purest form of iron
Wrought Iron. Contains less than 0.05% C. Anything more. Not a steel
Two major families of steel
Carbon and alloy
Steel numbering
First two digits alloy group. The last 2 carbon content
0.05-0.35% C
Low carbon steel. Lower strength and hardness
0.35-0.50 % C
Medium Carbon steel. Balance of strength and duct. Good wear resistance. Stuctyre Al steel in category
Examples of med-Carbon steel
Forging and high strength castings. Automotive part.
Why higher Carbon steel can’t be welded?
The heat causes residual stress which will cause cracking. Oxygen-induced cracking. needs pre and post heating/cooling
What is v crack of residual stress on steel called
HAZ( Heat Affected Zone)
Stainless steel has a noticeable blank content.
Chromium content. minimum of 10 %
Steels with additional elements added to increase properties
Alloy Steel
What makes a steel corrosion resistant
high carbon and chromium content
Stainless steel types
- Austenitic 2. Super- Austentictic 3. Ferritic. 4. Duplex Steel. 5. Martensititc 6. Precitpation hardening Martensitic
When you heat An Austentic iron above 1300” degrees
it changes between BCC to FCC stucure.
Austnetic
High corrosion resitant. high chromium content
Ferritic
Steel with high iron. lower corrosion res than other Stainless steel.
Causes cracking in the welding process for mild carbon steels
Residual Stresses
0.5 - 1.00 % C.
High cabron contnet. prosisblity of crackign and brittleness. Very hard and Very Strong after heat treatment
Fewer alloys than other alloy steels. easily weldable. more corrosion resistant
Low Alloy Steel
Steels that are well suited for making different tools and tool parts. High Strenght. Wear Strength.
Tool Steels
two types of magnet
Temporary and permanent
Spring steel
a stainless steel types
two types of forging
Forging uses a deformation usually a hammer. Hot forging ( is heated at Recrytalization temp) while cold forging is at room temperature. Cold hardenes them and Heat forges.
95 % of all metals produced in the world are these metals.
Iron and Steel
Low iron ore like substance. Contains a percentage of magnetite Firing at high temperatures it oxides the magnetite into Hameitite.
Talconite. Talconite pellets
Iron produced from a process getting rid the oxygen and oxides on the iron.
Direct Reduced Iron.
A process that is used to remove the gangue or other impure minerals in metals
Steps Crushing then various processes of procceisn goremoving impurities.
Benefiticaiton
Uses elecctrodes with Carbon and Man. to remove iron.
DirectElectirc arc iron
