SAE AS 4877F:2017 pdf free download – Bolts and Screws,Nickel Alloy UNS N07718, Classification: 185 ksi/1200 °F Procurement Specification

SAE AS 4877F:2017 pdf free download – Bolts and Screws,Nickel Alloy UNS N07718, Classification: 185 ksi/1200 °F Procurement Specification.
3.3.2.1 Heating Equipment
Furnaces may be any type ensuring uniform temperature throughout the parts being heated and shall be equipped with, and operated by, automatic temperature controllers arid data recorders conforming to AMS2750. The heating medium or atmosphere shall cause no surface hardening by carburizing or nitrlng. The heat treatment atmosphere or medium shall not cause any surface contamination except as permitted by 3.3.3. On uriplated bolts, discoloration from heat treatment is acceptable but no scale is permissible.
3.3.2.2 Sokition Heat Treatment
Headed blanks shall be solution heat treated by heating to a temperature within the range 1725 to 1850 °F, holding at the selected temperature within ±25 °F for 1 hour ± 0.1 hour, and quenching in oil, water, or an inert gas.
3.3.2.3 Precipitation Heat Treatment
After solution heat treatment as in 3.3.2.2. headed blanks shall be precipitation heat treated by heating to 1325 °F ± 15 °F
in a controlled atmosphere. holding at heat for 8 hours ±0.25 hour, furnace cooling at 100 F ± 15 °F per hour to 1150 F ±
15 °F, holding at 1150 °F ± 15 °F for 8 hours ± 0.25 hour and cooling at a rate equivalent to air cooL Instead of the 100 °F
per hour cooling rate to 1150°F ± 15 °F, parts may be furnace cooled at any rate provided the time at 1150°F ± 15°F is
adjusted 10 give a total precipitation heat treatment time of approxately 18 hours.
3.3.3 Oxide Removal
Surface oxide and oxide penetration resulting from prior heat treatment shall be removed from the full body diameter and bearing surface of the head of the solution and precipitation heat treated blanks prior to cold rolling the fillet radius and rolling the threads. The oxide removal process shall produce no intergranular attack or corrosion of the blanks. The metal removed from the bearing surface of the head and the full body diameter of the shank shall be as lithe as practicable to obtain a clean, smooth surface.
3.3.4 Cold Rolling of Fillet Radius
After removal of oxide as in 3.3.3, the head-to-shank fillet radius of parts having the radius complete throughout the circumference of the part shall be cold rolled. Cold rolling shall be sufficient to remove all visual evidence of grinding or tool marks. Distortion due to cold rolling shall conform to Figure 1. unless otherwise specified on the part drawing. It shall not raise metal more than 0.002 inch above the contour at A or depress metal more than 0.002 inch below the contour at “B” as shown in Figure 1: distorted areas shall not extend beyond C as shown in Figure 1. In configurations having an undercut connected with the fillet radius, the cold rolling will be required only for 90° of fillet arc, starting at the point of tangency of the fillet radius and the bearing surface of the head. For shouldered boIls having an unthreaded shank diameter larger than the thread major diameter and having an undercut connected with a fillet between the threaded shank and the shoulder of the unthreaded shank, the cold rolling will be required only for 90° of fillet arc, starting at the point of tangency of the fillet radius and the shouldered surface of the unthreaded shank. The shank diameter on full shank close tolerance bolts shall not exceed the nominal thread diameter after cold rolling the head-to-shank fillet radius.
3.6.5.2 Machined Test Specimens
If the size or shape of the part is such that a stress.rupfure test cannot be made on the part, a test specimen prepared as in 4.5.7, maintained at 1200 °F ± 5 F while a load sufficient to produce an initial axial stress of 100 ksi is applied continuously, shall not rupture in less than 23 hours. Tests shall be conducted in accordance with ASTM El 39. Specimens may be required by purchaser to perform confirmatory tests.
3.6.6 Ultimate Shear Strength
Finished parts having a close toleranced full shank as in AS1 132 shall have an ultimate double shear load not lower than that specified In Table 1. The double shear test may be discontinued without a complete shear failure after the ultimate shear load has been reached, first measunng and recording the maamum double shear load achieved. Shear bolts having special shank diameters shall have the minimum ultimate double shear load based on 111 ksi minimum shear strength. Shear tests are not required for countersunk head fasteners having a grip less than 2.5 times the nominal diameter or protruding head fasteners having a grip less than 2 times the nominal diameter. Shear test are not required for the followrng conditions.