Answer:
The principal elements are Iron, Nickel, Chromium
It has 0.37% to 0.43% Carbon
It is hardenable.
It can be hardened by cold working, annealing, quenching.
Step-by-step explanation:
A)
The chemical composition of AISI 4340 Steel are as follows:
Iron --- 95% to 96%
Nickel --- 1.6% to 2.0%
Chromium --- 0.7% to 0.9%
Manganese --- 0.6% to 0.8%
Carbon --- 0.37% to 0.43%
Molybdenum --- 0.2% to 0.3%
Silicon --- 0.15% to 0.30%
Sulfur --- 0.040%
Phosphorous --- 0.0350%
So, the principal alloy elements from this composition are Iron, Nickel and Chromium
B)
The carbon content in this alloy is 0.37% to 0.43%
C)
Yes, it can be hardened.
D)
It can be Hardened by Cold Working, Annealing or Quenching.