Stainless Steel - Grade 630/17-4 PH

Stainless Steel - Grade 630 is also referred to as 17-4PH. It is a special grade of martensitic stainless steel and is very strong and hard. Such great strength and hardness in grade 630 are achieved through a process called precipitation hardening.

Key Benefits of Stainless Steel - Grade 630

One of the key benefits of Grade 630 stainless steel is that it is available in solution-treated conditions. In this condition, the steel can be easily machined, that is, it may be cut and shaped easily and then age-hardened to get high strength. Age-hardening is done at comparatively low temperatures so that little distortion or warping occurs. This makes Grade 630 particularly suitable for the manufacture of long shafts and other components which are required to have precise dimensions and that do not have to be straightened after heat treatment.

Chemical Composition of Stainless Steel - Grade 630

It has a carefully balanced chemical composition to offer Grade 630 stainless steel its magnificent properties. The chemical composition of grease 630 is as follows:

Carbon

0.07%

Manganese

1%

Silicon

1%

Phosphorus

0.04%

Sulfur

0.03%

Chromium

17.5%

Nickel

5%

Phosphorous,

5%

Niobium and Tantalum

0.45%

 

Physical Properties of Stainless Steel - Grade 630

The physical properties of Grade 630 stainless steel make it very suitable for a multitude of applications. Some of the key physical properties include:

Density

7750 kg/m³

Elastic Modulus

197 GPa

Electrical Resistivity

800 nΩ·m

 

Mechanical Properties of Stainless Steel - Grade 630

The mechanical properties of Grade 630 stainless steel are excellent and very important for its use in different applications.  Some of its mechanical properties are as follows:

Yield Strength

1000 MPa

Elongation

15% (in 50mm)

Hardness (Rockwell C)

38 Max

Hardness (Brinell)

363 Max

 

Thermal Properties of Stainless Steel - Grade 630

Grade 630 stainless steel has good oxidation resistance; it does not rust easily when exposed to air and moisture. However, it must not be exposed for a long time in the temperature range of 370-480°C as this can significantly lower its toughness. It must also not be used at temperatures higher than the age hardening temperature for its hardness and strength.

Mean Coefficient of Thermal Expansion

10.8 µm/m/°C

Thermal Conductivity

18.4 W/m·K

Specific Heat (0-100°C)

460 J/kg·K

 

Applications of Stainless Steel - Grade 630

Stainless Steel - Grade 630 has wide usage in industries due to its wonderful mechanical properties and resistance to stress-corrosion cracking. Some common uses include:

  • Valves and gears
  • Oil field equipment
  • Propeller shafts
  • Pump shafts
  • Valve spindles
  • Aircraft and gas turbines
  • Nuclear reactors
  • Paper mills
  • Chemical processing equipment

Stainless Steel - Grade 630 has high strength, hardness, resistance to corrosion, and stress cracking. It finds usage in many highly critical applications across various industries.