Inconel Alloy 625 Applied for ASME Boiler & Pressure Vessel Codes
Inconel alloy 625, designated as UNS N06625, has the nominal composition of 60Ni–22Cr–9Mo–3.5Cb. Materials made from Inconel alloy 625 are widely applied for projects designed to ASME Boiler & Pressure Vessel Codes. They may be furnished in either solution annealed (Grade 2) or annealed (Grade 1) conditions. Its product forms cover plate, sheet, strip according to ASME SB-443/ ASTM B443; seamless pipe and tube according to ASME SB-444/ ASTM B444; bar according to ASME SB-446/ ASTM B446; forgings according to ASME SB-564/ ASTM B564, welde pipe according to ASME SB-705/ ASTM B705; welded tube according to ASME SB-704/ ASTM B-704; seamless & welded pipe fittings according to ASME SB-366/ ASTM B366.
An important note is that alloy 625 in the annealed condition is subject to severe loss of impact strength at room temperatures after exposure in the range of 1000°F to 1400°F. Generally, the applicability and maximum temperature limits of Inconel alloy 625 in different product forms and conditions are listed below:
- All product forms of alloy 625 mentioned above in both solution annealed and annealed conditions can be used for ASME Section I with maximum temperature limit of 1100°F, ASME Section VIII-1 Division 1 with maximum temperature limit of 1600°F, and Section XII with maximum temperature limit of 650°F.
- In certain cases, only the material (UNS N06625) in annealed condition may be applied for ASME Section III with maximum temperature limit of 800°F; Inconel 625 alloy bar can be applied for bolting materials in ASME Section VIII Division 1, Section VIII Division 2, and Section XII with maximum temperature limits of 1200°F, 800°F, and 650°F, respectively.