ASTM F2832-11(R2021) pdf free download

ASTM F2832-11(R2021) pdf free download.Standard Guide for Accelerated Corrosion Testing for Mechanical Fasteners
1. Scope
1.1 This guide covers test procedures for performing accel- erated tests to evaluate relative corrosion resistance of various coatings applied to mechanical fasteners. Corrosion mecha- nisms such as general and crevice corrosion may be evaluated with this method. Test duration may be selected to achieve any desired level of corrosion exposure and provides a frame of reference to determine relative coating resistance to corrosion. Fasteners tightened to a desired tension and subjected to this test procedure may be evaluated to simulate a variety ofservice conditions. Without large amounts ofaccumulated field results, it is difficult to relate test duration or the number of test cycles to actual service life for a given application. 1.2 This standard is not intended to cover tests of driven fasteners such as nails, staples, screws and lag bolts. 1.3 Units—The values stated in SI units are to be regarded as standard. No other units ofmeasurement are included in this standard. 1.4 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 ofregulatory limitations prior to use. 1.5 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.
Coupons shall be included with fasteners to be tested to verify that uniform amounts of corrosion have been produced by tests. Refer to Fig. 1, Fig. 1 (a) and Fig. 1(b) and Table 3. Inclusion of a metal loss coupon assists in making comparisons from one test to another and allows one to quantify a repeatable test. 5.2 A fog humidity cabinet shall be used in which salt mist applications are coupled with high humidity and moderately high temperature. Water fog or visible water droplets on parts being tested shall be continuous after equilibrium is reached. Dry-off may be sequenced manually or automatically. 5.3 Racks suitable for supporting bolt or screw assemblies shall be agreed upon between supplier and purchaser. Test results shall always state materials used for racks during testing. Nylon or other suitable nonmetallic washers shall be installed to prevent bolt or screw heads or test coupons from contact with test racks. See Fig. 1 and 7.8.
6. Salt Mist Application and Dry-off
6.1 Salt solution shall conform to requirements of Table 4. Solutions shall be sprayed by nozzles to provide a mist such that test fasteners and coupons are thoroughly wet and dripping when examined visually. Solution collection rates shall con- form to Practice B117. Salt accumulations shall have been rinsed away during the salt solution spray application. 6.2 For the drying part of a cycle, a dry-off environment area shall be maintained with sufficient air circulation to assure uniform temperature and shall allow thorough drying of tested fasteners and coupons. Temperature and humidity conditions are defined in Table 4.
7. Test Procedure
7.1 Fasteners to be tested with salt spray, shall be sampled in accordance with Practice F1470, Sample Level B. 7.2 Each fastener to be tested shall be installed through its corresponding rack using nonmetallic washers as to maintain a minimum of 5 mm spacing between underside of the head and surface of the rack. The washers for any testing protocol shall be identical. Fig. 1(a) and Fig. 1(b) provide an illustrative representation. Holes in test racks shall be offset to avoid dripping from one test fastener onto another. Fastener load shall be achieved through finger tightening (Fig. 1 illustrates the assembly). If higher loads or proof load tightening is required then the load level and method of tightening shall be by agreement between supplier and purchaser.