ASTM F945-2019 pdf free download

ASTM F945-2019 pdf free download.Standard Test Method for Stress-Corrosion of Titanium Alloys by Aircraft Engine Cleaning Materials
1. Scope
1.1 This test method establishes a test procedure for deter- mining the propensity of aircraft turbine engine cleaning and maintenance materials for causing stress corrosion cracking of titanium alloy parts. 1.2 The evaluation is conducted on representative titanium alloys by determining the effect of contact with cleaning and maintenance materials on tendency of prestressed titanium alloys to crack when subsequently heated to elevated tempera- tures. 1.3 Test conditions are based upon manufacturer’s maxi- mum recommended operating solution concentration. 1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability of regulatory limitations prior to use. For specific precautionary statements, see 5.3 and 5.6. 1.6 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Significance and Use
3.1 Because of the tendency of prestressed titanium alloy parts to crack if heated while in contact with certain chemical reagents, it is necessary to ensure that cleaning and mainte- nance materials will not initiate stress corrosion of titanium alloys under controlled conditions. For test specimens, two common titanium alloys are selected, one that is very suscep- tible (AMS 4916) and one that is not very susceptible (AMS 4911) to stress corrosion cracking.
4. Apparatus
4.1 Measuring Device capable oflinear measurement with a 60.01-in. (60.25-mm) tolerance. 4.2 Press Forming Apparatus 4 with 0.56-in. (14-mm) diam- eter mandrel capable of producing approximately 65° bends in 0.050-in. (1.25-mm) titanium alloy sheet specimens.4.3 Beakers or Small Tanks for containment of cleaning, rinsing, and test solutions, appropriately lined to prevent contamination of the solutions by container materials. 4.4 Vise, capable of precise manipulation at jaw opening of 0.65 in. (16.5 mm). A standard sheet metal worker’s vise with a 3-in. jaw has been found satisfactory. 4.5 Air Circulation Furnace capable of operating at 900 °F (480 °C) with control to 620 °F (10 °C). 4.6 Magnifier capable of 20-diameters magnification. 4.7 Microscope capable of 500-diameters magnification. 4.8 Bolt, stainless steel, 0.25-in. (6-mm) diameter with stainless steel washers and nut. 4.9 Test Specimens, AMS 4911 and AMS 4916 Titanium Alloys—with specimens prepared from the same sheet stock for each alloy and cut parallel to the rolling direction to the dimensions ofFig. 1. The specimen edges shall not be deburred or otherwise relieved before testing. 4.10 Cotton Gloves, white. 4.11 Volumetric Flask of Low Sodium Glass with Ground Glass Stopper, 1000 and 100 mL. 4.12 Volumetric Pipette, 10 mL. 4.13 Volumetric Flask with Ground Glass Stopper, 100 mL.
5. Reagents and Materials
5.1 Purity of Reagent—Reagent grade chemicals shall be used in all cases. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Commit- tee on Analytical Reagents of the American Chemical Society, where such specifications are available. 5 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of analysis.5.2 Purity ofWater—Unless otherwise indicated, references to water shall be understood to mean reagent water conforming to Specification D1193 Type IV. 5.3 Cleaning Solution, mix 35 volume % nitric acid (42° Be’) (Warning —See Annex A1.2) and 3 volume % hydro– fluoric acid (70 %) (Warning—See Annex A1.3) with reagent water. 5.4 2–Propanol (Isopropanol), HPLC grade. 5.5 Salt Solutions: 5.5.1 100–ppm sodium chloride solution in 2–propanol. 5.5.1.1 Preparation of1000–ppm NaCl in 2–Propanol Stock Solution (ShelfLife Three Months in Flask, see 4.11)—Weigh 1.000–g NaCl 6 0.001 g into a 1000–mL volumetric flask. Add 250- 6 25-mL reagent water and stir to dissolve. Fill to the mark with 2–propanol and mix.