Chemical composition, mechanical properties, standards of fastener material Alloy 625 (2.4856).

Alloy 625 is a nickel-based alloy with excellent corrosion resistance, containing molybdenum, niobium and iron.

• Density: 8.44 g/cm³

• Melting range: 1290-1350°C

• Specific heat capacity: 410 J/kg(°C)

• Curie temperature: -196°C

• Magnetic permeability at 200 Oersted (15.9 kA/m): 1.0006

• Coefficient of thermal expansion: 12.8 (21 - 93°C µm/m-°C)

• Thermal conductivity: 9.8 W/m(°C)

• Electrical resistivity: 1.29 mm²/m

Physical and thermal properties:

• In the annealed state, Alloy 625 has excellent resistance to pitting, crevice corrosion, stress corrosion and corrosion fatigue.

• It has good resistance to mineral acids (such as nitric acid, phosphoric acid, sulfuric acid and hydrochloric acid) as well as alkalis and organic acids.

• Alloy 625 is widely used in the oil and gas industry, chemical processing industry, marine engineering and environmental engineering.

Chemical composition analysis:

• Nickel (Ni): minimum 58.0%

• Chromium (Cr): 20.0-23.0%

• Molybdenum (Mo): 8.0-10.0%

• Niobium (Nb): 3.15-4.15%

• Iron (Fe): maximum 5.0%

• Carbon (C): maximum 0.10%

• Manganese (Mn): maximum 0.50%

• Silicon (Si): maximum 0.50%

• Sulfur (S): maximum 0.015%

• Aluminum (Al): maximum 0.40%

• Titanium (Ti): maximum 0.40%

• Phosphorus (P): maximum 0.015%

• Cobalt (Co): maximum 1.0%

Mechanical properties (annealing):

Creep strength (1000 hours): 52.0 ksi (360 MPa) at 650°C, 23.0 ksi (160 MPa) at 760°C, 7.2 ksi (50 MPa), 2.6 ksi (18 MPa) at 980°C

Specification:

• UNS:N06625

• ASTM: B366, B443, B444, B446, B564, B704, B705, B751, B775, B829

• ASME: SB366, SB443, SB444, SB446, SB564, SB704, SB705, SB751, SB775, SB829

• NACE/ISO: MR0175/ ISO15156ISO: 3072, 3074, 3076 (NA21)

• DIN: 17744, 17750-17754

• Vd TÜV: 499

• EN:10095