Which row of the table correctly describes the property changes that occur after tempering quench-hardened steel?
ENGINEERING, PPT 2020 HSC 25b
Members of steel trusses are often connected using metal rivets as shown.
Describe the hot working process that the rivet has undergone to create the resulting structure. Support your answer by completing and labelling the diagram of the sectioned rivet. (3 marks)
--- 7 WORK AREA LINES (style=lined) ---
Show Answers Only
→ For hot working to be successful, the rivet has to be heated above the recrystallisation temperature of the material.
→ A riveting gun is then used to hot forge the head of the rivet into place.
→ This causes grain flow to form around the head of the rivet, as shown in the image above.
Show Worked Solution
→ For hot working to be successful, the rivet has to be heated above the recrystallisation temperature of the material.
→ A riveting gun is then used to hot forge the head of the rivet into place.
→ This causes grain flow to form around the head of the rivet, as shown in the image above.
♦♦♦ Mean mark 26%.
ENGINEERING, PPT 2020 HSC 18 MC
The grain structure of a material has changed over time from that shown in microstructure `A` to that shown in microstructure `B`.
What heat treatment process has the material undergone to cause this change?
- Tempering
- Normalising
- Quench hardening
- Precipitation hardening