Steel Flashcards
(25 cards)
What is steel?
An alloy of iron containing less than 2% carbon.
What is mild steel?
A common type of steel with less than 0.3% carbon and beneficial elements like manganese and silicon.
What are the impurities commonly found in mild steel?
- Phosphorus
- Sulfur
- Oxygen
- Nitrogen
How does cast iron differ from steel?
Contains 3-4% carbon and more impurities, making it hard but brittle.
What is wrought iron?
Contains even less carbon than most steel alloys, resulting in a malleable but weaker material.
How does carbon content affect iron-based metals?
Significantly influences their properties; optimal carbon levels in mild steel enhance structural properties.
What is the primary process used to produce most steel?
Basic oxygen process.
Describe the basic oxygen process.
A lance introduces high-pressure oxygen into molten iron and scrap steel to remove excess carbon and impurities.
What additional metallic elements may be added to steel?
- Manganese for abrasion resistance
- Molybdenum for strength
- Vanadium for strength and toughness
- Nickel and chromium for corrosion resistance, toughness, and stiffness
What is ASTM A992 used for?
Preferred for standard wide-flange structural shapes.
What is the significance of ASTM A36?
Historically the most common steel used in building frames.
What is stainless steel?
Produced by adding nickel and chromium, offering enhanced corrosion resistance.
What is galvanization?
A process that involves applying a zinc coating to protect steel from corrosion.
What is weathering steel?
Designated as ASTM A588, it develops a protective oxide coating when exposed to the atmosphere.
What is the structural mill process?
Beam blanks are reheated and passed through rollers to shape the metal into the desired form and size.
What are wide-flange shapes?
Shapes that have largely replaced older American Standard shapes due to superior structural efficiency.
What is a rivet?
A steel fastener with a cylindrical body and a formed head.
What process is used to install a rivet?
Heating it to white heat, inserting it through holes, and forming a second head using a pneumatic hammer.
True or False: Riveting is still the dominant fastening technique in modern steel frame construction.
False.
What types of bolts are used in steel frame construction?
- High-strength bolts (ASTM A325 and A490)
- Lower-strength carbon steel bolts (ASTM A307)
What are bearing-type connections?
Bolts are installed to a snug-tight condition, primarily stressed in shear under normal load conditions.
What are slip-critical (friction-type) connections?
Bolts are preloaded to create friction, resisting movement and stressed in tension.
Fill in the blank: Bolts are inserted into holes that are _______ larger than the bolt diameter.
1/16 inch (2 mm)
What is the primary advantage of welding in steel construction?
Allows for the joining of steel frame members as if they were a single, monolithic structure.
