Precipitation-hardening nickel-chromium-iron alloy strengthened by the \u03b3’ (Ni\u2083(Ti,Al)) precipitate formed with titanium and aluminium. Bought for parts that need high tensile and yield strength up to about 700 \u00b0C, stress-rupture strength up to about 815 \u00b0C and oxidation resistance up to about 980\u2026<\/div>\n<\/div>\n
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Forms<\/div>\n
Round bar \u00b7 flat bar \u00b7 plate \u00b7 sheet \u00b7 tube \u00b7 forging. All forms supplied to order. Wire and strip are not among the forms sold on this page; the AMS 5698 \/ AMS 5699 spring wire specifications are listed below for information only.<\/div>\n<\/div>\n
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Standards<\/div>\n
AMS 5667<\/b> \u2014 bars, forgings, rings and stock for forgings, rings and heading; supplied EQUALIZED, precipitation-hardenable. \u00b7 AMS 5668<\/b> \u2014 bars, forgings, rings and forging stock; supplied 1149 \u00b0C (2100 \u00b0F) SOLUTION AND PRECIPITATION HEAT TREATED. \u00b7 AMS 5669<\/b> \u2014 bars; consumable electrode remelted or vacuum induction melted (premium melt). \u00b7 AMS 5670<\/b> \u2014 bars, forgings, rings and stock for rings, forgings and heading; 982 \u00b0C (1800 \u00b0F) SOLUTION HEAT TREATED, precipitation-hardenable. \u00b7 AMS 5671<\/b> \u2014 bars, forgings, rings and forging stock; consumable electrode or vacuum induction melted, 982 \u00b0C (1800 \u00b0F) SOLUTION HEAT TREATED, precipitation-hardenable. \u00b7 AMS 5747<\/b> \u2014 bars, forgings, rings; SOLUTION HEAT TREATED, precipitation-hardenable. \u00b7 AMS 5542<\/b> \u2014 sheet, strip, plate; supplied ANNEALED. \u00b7 AMS 5598<\/b> \u2014 sheet, strip, plate; consumable electrode remelted or vacuum induction melted, SOLUTION HEAT TREATED, precipitation-hardenable. \u00b7 AMS 5582<\/b> \u2014 seamless tubing; solution heat treated, precipitation-hardenable to 1069 MPa (155 ksi) tensile strength. \u00b7 AMS 5583<\/b> \u2014 seamless tubing; VACUUM MELTED, solution heat treated, precipitation-hardenable to 1172 MPa (170 ksi) tensile strength. \u00b7 AMS 5698<\/b> \u2014 wire; solution heat treated (earlier revisions: ‘No. 1 Temper’), precipitation-hardenable. \u00b7 AMS 5699<\/b> \u2014 wire; spring temper, precipitation-hardenable. \u00b7 ASTM B637 \/ ASME SB-637 \u2014 bars, forgings and forging stock; defines three separate heat treatment types for N07750: Type 1, Type 2 and Type 3. \u00b7 EN 10269 \u2014 NiCr15Fe7TiAl \/ 2.4669; fasteners (bolts, studs) with specified elevated and\/or low temperature properties.
For this alloy an AMS number defines the product form AND the heat treatment condition as delivered; the numbers differ mostly not in chemistry but in solution temperature and in whether the material is shipped aged or ready to be aged.<\/span><\/div>\n<\/div>\n\n
Advantage<\/div>\n
Strengthening comes from the \u03b3’ (Ni\u2083(Ti,Al)) precipitate, which is stable to a higher temperature than the Nb-based \u03b3” (Ni\u2083Nb) precipitate of niobium-hardened alloys.<\/div>\n<\/div>\n
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Welding<\/div>\n
Before welding the material must be in the annealed, solution heat treated or equalized condition; fully precipitation-hardened material must not be welded and then aged \u2014 the parent metal can crack.<\/div>\n<\/div>\n
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Limits<\/div>\n
In high-temperature pressurised water (light water reactor primary circuit) the alloy is susceptible to intergranular stress-corrosion cracking; X-750 support pins in pressurised water reactors have failed this way.<\/div>\n<\/div>\n