7225 Thyssenkrupp Steel Round Bar

Thyssenkrupp 7225
Quenched & Tempered Alloyed Engineering Steel Grade

Characteristics

7225 steel very common Quenched & Tempered alloyed engineering steel grade with high intensity, high hardenability. 7225 classify in the group of low alloy which provide high strength through combination of Chromium and Molybdinum. It has a small distortion afer quenching, a ghigh creep strength and lasting intensity afer processing of high tempreature. This result in impact resistance at low temperature.

7225 It’s one kinds of high quality alloy structural steel. 1.7225 is the EN numeric designation for this material. 42CrMo4 is the EN chemical designation. Supplied 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.

Standards

Europe : DIN EN 10083-1 / DIN EN 10250-3 / DIN EN 10263-4 USA : ASTM A29 / ASTM A 193 / ASTM A 320 / ASTM A 322 / ASTM A 331 / SAE J 404

Outstanding Features

• High Strength
• High toughness
• Wear resistance
• Resistance to fatigue
• Forgeability
• 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.

Equivalent

AISI 4140, DIN 42CrMo4, ASSAB 709, VCL140, JIS SCM 440, EN 1.7223, EN 1.7225, EN 1.7227, EN 1.3563,

Availability

Round bar

Sizes: 10mm – 590mm

Chemical composition: ( % )

C	Si	Mn	P	S	Ni	Cr	Mo	Cu
0.38-0.45	0.15-0.40	0.60-0.90	0.035	0.035	<0.25	0.90-1.20	0.15-0.30	0.030

Mechanical Properties

Hardening Temp : 820 – 850 °C
Normalizing: 840 – 880 °C
Hot Forming: 800 – 1100 °C
Ouenching Medium : Oil or Water
Hardness Supplied (HB):

Supplied Condition

• Hot rolled bars in Quenched and Tempered condition (DIN EN 10083-1)
• Hot forged bars in Quenched and Tempered condition (DIN EN 10250-3)

Application

It’s mainly used for making various kinds of machinery, automobile, mining spare part, the gearwheel of the engine, the driving gear of supercharger, the abckshaft, the conncetingrob and the pinchock under the high pressure. Parts for power train applications, cold formed fastener components, shafts, gears, drill collars for the oil exploration, etc.