ThePipingMart Blog Grades Hastelloy G30 (UNS N06030) – Composition, Properties and Uses

Hastelloy G30 (UNS N06030) – Composition, Properties and Uses

Hastelloy G30

Hastelloy G30 is a nickel-based alloy known for its exceptional resistance to corrosion and pitting in aggressive environments. This superalloy is widely used in various industries such as chemical processing, oil and gas, pharmaceuticals, etc. In this blog post, we will delve into the world of Hastelloy G30 and explore its composition, physical and mechanical properties, uses, hardness, heat treatment, welding, and, most importantly, its corrosion resistance.

Hastelloy G30 Composition

Hastelloy G30 is a highly alloyed nickel-chromium-molybdenum-tungsten alloy with a small amount of iron. It also contains cobalt, vanadium, and nitrogen. The unique composition of Hastelloy G30 provides outstanding resistance to both reducing and oxidizing acids, making it ideal for applications where corrosion resistance is paramount.

Element Content (%)
Nickel, Ni 43
Chromium, Cr 28.0-31.5
Iron, Fe 13-17
Cobalt, Co  5
Molybdenum, Mo 4-6
Tungsten, W 1.50 – 4
Manganese, Mn  1.50
Copper, Cu 1 – 2 .40
Silicon, Si 0.8
Phosphorous, P  0.040
Carbon, C  0.030
Sulfur, S  0.020

Hastelloy G30 Physical Properties

Hastelloy G30 exhibits excellent physical properties such as high tensile strength, good ductility, and low thermal expansion. The density of this alloy is 8.22 g/cm³. It has a melting point of 1399°C and a boiling point of 3045°C. It also shows an excellent thermal conductivity of 8.62 W/m·K.

Properties Metric Imperial
Density 8.22 g/cm³ 0.297 lb/in³
Melting point 1371ºC 2500ºF

Hastelloy G30 Mechanical Properties

Hastelloy G30 has exceptional mechanical properties that make it suitable for high-stress applications. The yield strength of this alloy is 416 MPa, whereas its ultimate tensile strength is 760 MPa. It has a hardness of 290 HB.

Properties Metric Imperial
Tensile strength 1096 MPa 159000 psi
Yield strength (@0.2%) 1000 MPa 145000 psi
Modulus of elasticity (plate heat treated to 1177°C, rapid quenched) 202 GPa 29300 ksi
Elongation at break (in 50.8 mm) 12% 12%
Reduction of area 57% 57%
Hardness, Brinell (converted from Rockwell C hardness) 304 304
Hardness, Knoop (converted from Rockwell C hardness) 326 326
Hardness, Rockwell C 32 32
Hardness, Vickers (converted from Rockwell C hardness) 316 316

Hastelloy G30 Equivalents

Properties Metric Imperial
Thermal expansion co-efficient (@30-316ºC/86-601ºF) 14.4 µm/m°C 8 µin/in°F
Thermal conductivity 10.2 W/mK 70.8 BTU in/hr.ft2.°F

Hastelloy G30 Equivalents

  • ASTM B366
  • ASTM B581
  • ASTM B582
  • ASTM B619
  • ASTM B622
  • DIN 2.4603

Hastelloy G30 Uses

Hastelloy G30 is a versatile alloy that finds applications in several industries. It is widely used in chemical processing plants for heat exchangers, condensers, and evaporators. It is also used to produce pharmaceuticals, agrochemicals, and organic chemicals. Other applications include the Oil & Gas industry, power generation, and food processing.

Hastelloy G30 Hardness

The hardness of Hastelloy G30 is dependent on its heat treatment. Generally, the alloy is supplied in the solution-annealed condition, which provides a hardness of around 130-160 HB. However, the hardness can reach up to 290 HB after precipitation hardening.

Hastelloy G30 Heat Treatment

Hastelloy G30 can be heat-treated to achieve different strength levels. The solution-annealing treatment is the most common, which is carried out at a temperature range of 1070-1150°C. The alloy is then quenched in water or rapidly cooled in air. Another heat treatment process is the precipitation hardening method, which increases the hardness of the alloy.

Hastelloy G30 Welding 

Hastelloy G30 is weldable using many methods like TIG, MIG, and arc welding. The choice of welding method depends on the application and the desired mechanical properties. Care must be taken during welding to preserve the corrosion resistance of the alloy.

Hastelloy G30 Corrosion Resistance

Hastelloy G30 is known for its exceptional corrosion resistance in oxidizing and reducing media. It resists attacks from hot and cold sulfuric acid solutions with concentrations up to 50%. It also resists nitric, acetic, and phosphoric acids, making it suitable for chemical processing industries. The alloy is also resistant to crevice and pitting corrosion in seawater and other chloride-containing environments.


Hastelloy G30 is a versatile nickel-based alloy with outstanding corrosion resistance in aggressive environments. It offers exceptional physical and mechanical properties, making it ideal for various industries. The alloy’s unique composition provides excellent corrosion resistance and high-stress capabilities, making it a popular choice for critical applications. Its heat treatment, welding ability, and corrosion resistance suit marine and chemical processing applications. Understanding the unique properties and features of Hastelloy G30 is critical in selecting appropriate materials for specific applications.

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