# YOUNG'S MODULUS OF STEEL

### What is Young's modulus (or Modulus of elasticity)?

Young's modulus (or Modulus of elasticity) is the measure of rigidity or stiffness of a material; the ratio of stress to the corresponding strain below the proportional limit. The modulus of elasticity is the slope of the stress-strain curve in the range of linear proportionality of stress to strain in the stress-strain curve.

### What is the formula of Young's modulus?

For most metals that are stressed in tension and at relatively low levels, stress and strain are proportional to each other through the relationship σ= Eε.

The constant of proportionality E (GPa or psi) is the modulus of elasticity, or Young’s modulus.

Here σ is engineering stress and ε is engineering strain.

The units of engineering stress are megapascals, MPa (SI) (where 1 MPa N/m2 ), and pounds force per square inch, psi (Customary U.S.). Engineering strain is unitless.

### What Is Young's Modulus Of Steel ?

Young's modulus of steel at room temperature is typically between 190 GPa (27500 ksi) and 215 GPa (31200 ksi). Young's modulus of carbon steels (mild, medium and high), alloy steels, stainless steels and tool steels are given in the following table in GPA and ksi.

 Modulus of Elasticity of Steel Material Modulus of Elasticity GPa ksi Modulus of Elasticity of Carbon Steels ASTM A228 (Music Wire) 210 30458 ASTM A36 200 29008 AISI 1010 205 29700 AISI 1018 205 29700 AISI 1020 205 29700 AISI 1025 190-210 27557-30458 AISI 1040 190-210 27557-30458 AISI 1045 205 29700 Modulus of Elasticity of Alloy Steels AISI 4037 190-210 27557-30458 AISI 4130 190-210 27557-30458 AISI 4140 190-210 27557-30458 AISI 4150 190-210 27557-30458 AISI 4340 190-210 27557-30458

Ref-1 Elastic modulus of carbon and low-alloy cast steels at room temperature are only slightly affected by changes in composition and structure. The modulus of elasticity, E, is about 200 GPa (29 × 106 psi). Increasing temperature has a effect on the modulus of elasticity.

A typical value of the modulus of elasticity:

- at 200 °C (400 °F) is about 193 GPa (28 × 106 psi);

- at 360 °C (680 °F), 179 GPa (26 × 106 psi);

- at 445 °C (830 °F), 165 GPa (24 × 106 psi);

- and at 490 °C (910 °F), 152 GPa (22 × 106 psi).

- Above 480 °C (900 °F), the value of the modulus of elasticity decreases rapidly.

 Modulus of Elasticity of Steel Material Modulus of Elasticity GPa ksi Modulus of Elasticity of Stainless Steels Grade 316 193 27992 Grade 405 200 29008 Grade 440C 200 29008 PH 15-7 Mo 200 29008 17-4 PH 196 28500 17-7 PH 204 29600 Modulus of Elasticity of Tool Steels D2 tool steel 210 30458 T1 tool steel 190-210 27557-30458 M2 tool steel 207 30000 W1 tool steel 205 29700 O1 tool steel 214 31000 O6 tool steel 207 30000 A2 tool steel 207 30000 A6 tool steel 207 30000 H13 tool steel 215 31200 H22 tool steel 190-210 27557-30458 P20 tool steel 207 30000 S7 tool steel 207 30000

Ref-1 For all practical purposes, modulus of elasticity of all tool steels in all conditions is about 210 GPa (30 × 106 psi) at room temperature. Elastic modulus decreases uniformly to about 185 GPa (27 × 106 psi) at 260 °C (500 °F) and about 150 GPa (22 × 106 psi) at 540 °C (1000 °F).

### Reference:

• Ref-1 Metals Handbook. Properties and Selection: Irons, Steels, and High- Performance Alloys. ASM International, 1990.