Through hardening steels

NC40SW

Spécifications

Common name
300M
EU
40NiSiCrMo7
USA
UNS: K44220
AISI: 300M
AMS
6417
6419
BS
S155
ASTM grade
32
ASTM std
A579

Composition

C
0.4
Ni
1.8
Cr
0.85
Mo
0.4
Si
1.6

Applications

• Shafts.
• Gears.
• Various mechanical parts.
• Heavily stressed aerospace parts.

Characteristics

• Melting: consumable electrode remelted steel.
• High mechanical properties.
• Good resistance to impact and fatigue.
• Maintains good properties at high temperatures.

Mechanical properties

Heat
treatment
UTS
(N/mm²)
0,2%
YS
(N/mm²)
A
(%)
KCU
(J/cm²)
T + Rv 600°C 1450 1300 14 60
T + 2xRv 300°C205017001250

Key to heat treatment symbols

Solution treated H Annealed R
Thermo-mechanical treatment TM Quenched and tempered T+RV
Sub-zero treatment F Solution treated and aged H+V

See also

MLX19

Stainless steels with structural hardening

819AW

Through hardening steels