Industrial Materials & Metallurgy Flashcards
7 cards from real CMS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Industrial Materials & Metallurgy flashcards as text
What is the purpose of the martensite transformation in steel hardening?
Answer: To produce a hard, body-centered tetragonal microstructure by rapid quenching
Rapid quenching traps carbon in the iron lattice, distorting it into a body-centered tetragonal structure called martensite, which is extremely hard and brittle.
Which alloying element is added to steel to improve its machinability by forming soft inclusions that act as chip breakers?
Answer: Sulfur
Sulfur forms manganese sulfide (MnS) inclusions in steel that act as internal lubricants and chip breakers, significantly improving machinability.
What is work hardening (strain hardening) in metals?
Answer: Increase in hardness and strength due to plastic deformation at room temperature
Work hardening is the increase in a metal's hardness and yield strength resulting from plastic deformation, which increases dislocation density and impedes further dislocation movement.
In the iron-carbon phase diagram, what is the maximum carbon content that defines the boundary between steel and cast iron?
Answer: 2.14% C
The boundary between steel and cast iron occurs at 2.14% carbon, which represents the maximum solubility of carbon in austenite at the eutectic temperature.
Which surface hardening process introduces nitrogen into the surface layer of steel to increase hardness without quenching?
Answer: Nitriding
Nitriding diffuses nitrogen into the steel surface at temperatures below the critical temperature, forming hard nitride compounds without requiring subsequent quenching.
What property describes a material's ability to absorb energy and deform plastically before fracturing, often measured as the area under the stress-strain curve?
Answer: Toughness
Toughness is the ability of a material to absorb energy before fracture and is represented by the total area under the engineering stress-strain curve.
Which type of corrosion occurs at the contact point between two dissimilar metals in the presence of an electrolyte?
Answer: Galvanic corrosion
Galvanic corrosion occurs when two dissimilar metals are in electrical contact in an electrolyte, with the more anodic (less noble) metal corroding preferentially.