M6.1 Ferrous Flashcards
What is a ferrous metal?
Alloy containing iron
What is steels density?
High
How is steel made less dense?
Alloying elements added to change characteristics
What does carbon allow steel to be?
Heat treated
In steel if carbon is high what is there a decrease in?
Malleability, weldability
What does sulphur cause steel to be?
Brittle
What does silicon cause steel to be?
Hardened
What does nickel add to steel?
Strength/hardness
What is stainless steel resistant to?
Corrosion, high temps
What are the 3 stainless steel grades? (AFM)
Austenitic, ferritic, martensitic
Can martensitic stainless steel be heat treated?
Yes
SAE means?
Society of automotive engineering
When identifying steels what does the first digit mean and the last 2 digits?
First digit = material type
Last 2 = carbon %
What does heating and cooling do to steel?
Changes it’s properties without changing shape or size
What is austenite? (FCCC)
Face centred cubic crystal
What is ferrite? (BCCC)
Body centred cubic crystal
What is martensite? (BCTC)
Body centred tetragonal crystal
What is critical temp?
Temperature at which change occurs
What is quenching.
Rapidly cooling of heated material
What is annealing?
Heat and allow to cool slowly
What is normalising?
Heated then soaked, left to cool at room temp
Why is tempering used?
To decrease hardness after quenching, only for high carbon steel
What is case hardening and why is it used?
Used for high pressure components, makes outer layer hard
What is direct hardening?
Flame hardening process, surface heated the cooled rapidly
What is flame hardening?
Heating with fire torch then quenching with water jet
What is induction hardening?
Heated with coil, quenched by water jets
