Engineering Board Exam Reviewer · Engineering Materials · hard
What is the mass fraction of cementite in pearlite (eutectoid steel, 0.76% C) just below 727 °C? (ferrite 0.022% C, cementite 6.70% C)
- 0.113
- 0.111
- 0.889
- 0.500
Answer
B. 0.111
Solution
W Fe3C = (0.76 - 0.022)/(6.70 - 0.022) = 0.111 ( 11%); the rest (0.889) is ferrite.
More Engineering Materials questions
- A 0.40% C steel is slowly cooled to just below 727 °C. What is the mass fraction of pearlite? (Use 0.022% C for ferrite and 0.76% C for…
- A steel has a plane-strain fracture toughness of 50 MPa · sqrt(m). For a design stress of 300 MPa and Y = 1.0, what is the critical crack…
- A steel plate with an edge crack 2 mm deep is loaded in tension at 200 MPa. Using K = 1.12 sqrt(π a), what is the stress intensity factor?
- A structural steel with a yield strength of 250 MPa is designed with a factor of safety of 2.5. What is the allowable stress?
- For steels, tensile strength ( MPa) 3.45 × BHN. What is the approximate tensile strength of a steel with a Brinell hardness of 229?
- A Brinell test uses a 10 mm ball under a load of 3000 kgf and produces an indentation 4.0 mm in diameter. What is the Brinell hardness…
- What is the maximum load a 10 mm diameter rod with an ultimate tensile strength of 500 MPa can carry?
- What is the true strain corresponding to an engineering strain of 0.20?
- At an engineering stress of 400 MPa, a specimen has an engineering strain of 0.20. Assuming constant volume, what is the true stress?
- A steel has a yield strength of 250 MPa and a modulus of elasticity of 200 GPa. What is its modulus of resilience?