API STD 6A718:2009 pdf download

API STD 6A718:2009 pdf download.Nickel Base Alloy 718 (UNS N07718) for Oil and Gas Drilling and Production Equipment.
b) Step 1—Vacuum induction melting (VIM).
Step 2—Either electroslag remelting (ESR) or electroflux remelting (EFR) or vacuum arc remelting (VAR). Optional Step 3—ESR or EFR or VAR.
4.1.3 Forging and Hot Working Requirements—Hot Work Reduction Ratio
The minimum total hot work reduction ratio shall be 4:1.
4.1.4 Heat Treating Requirements
4.1.4.1 Heat Treating Equipment Qualification and Calibration
The practice for qualification of heat-treating equipment shall be per the API 6A annex for qualification of heat-treating equipment or another internationally recognized standard. Furnaces shall be calibrated no less than once a year or when a furnace is moved, repaired or rebuilt. When the API 6A annex for qualification of heat-treating equipment is selected as the basis for furnace calibration, the requirements of the API 6A annex shall be treated as normative.
4.1.4.2 Temperature Monitoring
The material temperature shall be measured by use of either a contact surface thermocouple or a heat sink as described in API 6A or ISO 10423. The hold time shall not commence until the contact surface thermocouple or a heat sink reaches at least the minimum required material temperature.
The material manufacturer or material supplier shall maintain copies of the heat treating charts showing the material temperature as measured by the contact surface thermocouple or heat sink for five years minimum following the date of heat treatment.
4.1.4.3 Solution Annealing and Age Hardening
The production material and QTC(s) shall be solution annealed and age hardened in accordance with the following procedure.
Step 1—Solution anneal at a material temperature of 1870 °F to 1925 °F (1021 °C to 1052 °C) for one hour minimum to two and a half hours maximum.
Step 2—Cool in air, water, polymer or oil to ambient temperature.
Step 3—Age harden at a material temperature of 1425 °F to 1475 °F (774 °C to 802 °C) for six to eight hours.
Step 4—Air cool or faster to ambient temperature.
Optional Re-heat Treatment Steps—Complete re-heat treatment is permitted. Alternatively, re-aging within the parameters in Step 3 is permitted, provided the cumulative aging time does not exceed the maximum allowable aging time. All other requirements of shall be met by material that has been subjected to either of these optional steps.
If the material is re-aged without re-solution annealing, the testing required by 4.2.2, 4.2.3, 4.2.4, and 4.2.5 may be performed on remnants of the original QTC, provided the remnants are re-aged with the production material they represent.
4.2.1.2 Macroetch Examination and Acceptance Criteria
The macrostructure of the slice shall be examined and rated to all four classes in ASTM A604. The acceptance criteria are as follows.
Class 1 (Freckles)—No worse than Severity A.
Class 2 (White Spots)—No worse than Seventy A.
Class 3 (Radial Segregation)—No worse than Severity A.
Class 4 (Ring Pattern)—No worse than Seventy A.
4.2.2 Microstructural Analysis Requirement
4.2.2.1 Test Location, Method, and Frequency
Sample(s) of material with the same shape and equivalent round from each remelt ingot per heat treat lot shall be subjected to a microstructural analysis.
The sample(s) to be examined shall be a minimum 1/4 in. (6 mm) square and oriented longitudinally to the primary axis of grain flow. If the cross section of the material is less than 1/4 in. (6 mm), then the sample(s) shall be full cross section. The microstructural analysis shall be performed on material in the final heat treatment condition. Test locations shall be a minimum of 1.25 in. (32 mm) from a heat-treated end surface.