HOT WORKING PROCESSES Flashcards
Shaping metals at elevated temperatures above recryztallization temperature
Hot working
Benefits include: Improved Ductility, reduced strength, and ability to form complex shapes
Hot working
Common Applications: Forging, Rolling, Extrusion, and Drawing
Hot working
Process: Pulling a metal through a die to reduce its cross-sectional area
Hot Drawing
Types: Wire ________, Tube _________, and Rod ____________
Hot Drawing
Tube is pulled through a die with a mandrel inside to reduce cross sectional area
Tube Drawing
Process: Shaping a metal blank into a hollow form by forcing against a rotating mandrel
Hot Spinning
Process: Joining two pieces of metal together by applying heat and pressure
Pipe Welding
Process: Creating a hole in a metal sheet using a punch and die
Hot Piercing
Types: Butt Welding, Fillet Welding, Groove Welding
Pipe Welding
Metal is deformed plastically above recryztallization temperature but below the burning point.
Hot working Process
1/3 or 1/2 of the melting point of the metal
recrystallization temperature
Classifications: Rolling, Forging, Extrusion
Hot Working Processes
Metal is heated above recrystallization temperature and then passed through pair of rollers, rolling in the opposite direction but with the same speed to flatten it, lengthen it, and reduce cross-sectional area and obtain uniform thickness
Hot Rolling
Process in which metal is plastically deformed above the recrystalization temp. in the operation. It is commonly used to manufacture metal plates and sheets
Hot Rolling
Involves shaping of metal through localized compressive forces delivered through manual hammer or hammer machine and dies
Metal Forging
Process: Heating, deforming, and providing shape to the piece of metal using manual hammer or hammer machine and dies
Metal Forging
Metal is heated above recrystalization temp. and pushed through the die of the desired cross-section to convert to the desired shape
Hot Extrusion
Type of Extrusion:
- metal is forced to flow in the direction of feed of punch. Punch moves towards die during extrusion
Direct Extrusion
Common Product: Buckets, Bowls, and Lampshades, Brass trumpet,
Hot Spinning
Type of Extrusion:
Required higher force due to higher friction between billet and container
Direct Extrusion
Type of Extrusion:
also known as backward extrusion
Indirect Extrusion
Type of extrusion:
the metal billet is stationary and the die moves towards it. The die is attached to a hollow ram that fits over the billet. As the ram pushes the die against the billet, the metal flows backwards through the opening in the ram
Indirect Extrusion
EXAMPLES:
1. Nails, screws, bolts, and other
fasteners
2. Roofing, appliances
3. Frames, wheels, and
suspension parts.
4. Structural beams for buildings
and frameworks
5. Seamless Pipes and Tubes
6. Steel Rails
7. Metal Bars and Rods
8. Steel Sheets and Plates
Hot Rolling
