Which of the following pairs regarding the effect of alloying elements in steels are not matched correctly?

Which of the following pairs regarding the effect of alloying elements in steels are not matched correctly? Correct Answer Cobalt: It contributes to rerl hardness by hardening ferrite

Related Questions

Assertion 'a': Hardenability of steel can be increased by adding certain alloying elements.
Reason 'r': The alloying elements can provide a fine dispersion of alloy carbides
Steels containing up to 3% to 4% of one or more alloying elements are known as ________
Steels containing more than 5% of one or more alloying elements are known as ________
Alloy steels containing 0.05% to 0.15% of alloying elements are called _______