Machinery Steels : 7225

Main Characteristic

7225 classify in the group of low alloy which provide high strength through combination of
Chromium and Molybdinum. This result in impact resistance at low temperature.
Selling condition is quenched and tempered. Its convenience for further surface hardening
in order to enhance surface hardness. Caution is it is not suitable to use at temperature higher
than 480c since hardness will sharply fall. Besides, usage or tempering at level 230-270c might
cause condition of blue brittleness which will decrease its strength.

OutStanding Properties

   High Strength
   Resistance to fatigue
   Wear resistance
   Forgeability
   High toughness
   Moderate in machinability
   Not good for welding
   Moderate in control carbon loss at surface.
   Easy to quench, return hardness is 55-60HRC.
   Good for induction
   Can do nitriding , surface hardness is 650 HV
   Easy to do surface hardening suchas induction or nitriding
   Can be applied to mold in some case.

Application

7225 can be applied to machinery parts which require high strength such as powertrain,
joint steering wheel, wheel shaft, piston rod boring bit for oil and gas drilling, water pump parts,
high pressure pipe , big size gear, flange and locking tool.


C Si Mn Cr Mo S
0.38-0.45 0.10-0.40 0.60-0.90 0.90-1.20 0.15-0.30 0.02-0.04
Chemical Composition
ส่วนผสมทาง เคมี (%wt.)
AISI
JIS
DIN
สภาพจําหน่าย Selling Condition
สภาพหลังชุบ After Quenching
4140H
SCM 440H
1.7225 / 42CrMo4
ชุบแข็งและอบคืนตัว 28-33 HRC
ผิวแข็ง 55-60 HRC
7225 คุณสมบัติทั่วไป (General Characteristic)