Constant Fe – Alloying elements : C ; Si ; Mn : (a). Carbon ( C ) 0 – 1.5 % (2.3 %). Most important alloying element, strongly increasing the tensile strength and wear resistance; decisive for hardenability and maximum hardness of tool steels.

By : Farid Moch. Zamil

1. Constant Fe – Alloying elements : C ; Si ; Mn..

(a). Carbon ( C ) 0 – 1.5 % (2.3 %)

Most important alloying element, strongly increasing the tensile strength and
wear resistance; decisive for hardenability and maximum hardness of tool
steels.

Content for different steel grades :

0.01 – 0.10 % Steels with good forming capabilities, such as deep drawing
steels ; corrosion resistant ; not magnetising steels ; steels for
case hardening.

0.15 – 0.35 % General contruction steels with good tensile properties such
as elevated contruction steel, free machining steel.

0.40 – 0.80 % High tensile construction and tool steel such as heat treateble
steels, hot work steels, spring steels.

0.80 – 1.40 % Tool steels, wear resistance steels.

1.40 – 2.10 % Highly – Stressed cold work steels, high speed steels.

(b). Silicon ( Si ) 0.20 – 1.6 % (14 %) (Alloying Element)

Alloying and De – oxidation element (NMI – Si – Oxide), strongly increases
tensile properties, high elaticity limit (spring steels) ; Above 2 % Si only a
more limited elongation. Over 4 % practically unformable, increase in wear
resistance. Hardness scaling and corrosion resistance ; Above 10% Si (only
castable ) acid resistant ; for magnets, soft parts (dynamo and transformer
sheets) ; Si promotes graphite formation from cementite. Si is the primary
alloying element after C in grey cast iron.