Duplex process of steel making is a combination of

all of these

The electric process of steel making is especially adopted to
* alloy and carbon tool steel
* magnet steel
* high speed tool steel

L-D process

make the steel tougher and harder

make the steel ductile and of good bending qualities

The effect of manganese in improving the mechanical properties of steel depends on its carbon content. Manganese also reduces the critical cooling rate during hardening, meaning it increases the hardenability of steel. Its effect on hardenability is higher than other alloying elements. Hadfield steel is recognized for its ability to be work-hardened due to the addition of 10% to 14% of manganese.