Heat Treatment of Steel is one of 9 topics in the Grade 11 Mechanical Technology CAPS syllabus, covered across 3 lessons on Study Vault. Below are real practice questions from this topic with full worked answers.
Sample practice questions
Easy
1. What does the iron-carbon equilibrium diagram map, for the purposes of Grade 11 Mechanical Technology?
How the internal structure of an iron-carbon alloy changes across a range of temperatures and carbon content
The exact chemical composition of every steel grade
The cost of steel at different carbon percentages
The colour of steel at different temperatures only
Answer: How the internal structure of an iron-carbon alloy changes across a range of temperatures and carbon content — The iron-carbon equilibrium diagram maps how the internal (crystal) structure of an iron-carbon alloy changes across a relevant range of temperatures (roughly 500-900C) and carbon content (roughly 0-1.4%).
Easy
2. What is the approximate carbon content range relevant to the iron-carbon diagram as covered in Grade 11 Mechanical Technology?
Roughly 0% to 1,4%
Roughly 10% to 20%
Roughly 50% to 100%
Exactly 0% only
Answer: Roughly 0% to 1,4% — The relevant carbon content range is roughly 0 percent (essentially pure iron) up to 1,4 percent carbon, covering the practical range of carbon steels used in engineering.
Medium
3. What is the fundamental factor that heat treatment processes control, according to the iron-carbon diagram concept, to determine a steel's final properties after cooling?
Answer: cooling rate — Heat treatment fundamentally works by controlling how fast carbon steel cools from within the critical temperature range, which determines the final internal structure and properties.
