ISO 4969-2015 pdf free download

ISO 4969-2015 pdf free download.Steel Etching method for macroscopic examination
Acier — Méthode d’attaque pour examen macroscopique.
WARNING — Hydrofluoricacid should not be allowed to contact the skin since it can cause painful
serious ulcers if not washed off Immed lately.
5.3 The most commonly used solutions for macroetching iron and steel are Solution N° 1 and 2 in Table 1.
5.4 Renew the reagent as soon as its concentration is too low to be effective on etching.
6 Procedure
6.1 Hot etching and room temperature etching
6.1.1 Immerse the test piece in the acid bath, which can be heated. For large test pieces, it might bc useful to pre-heat them to the temperature of the bath.
6.1.2 Many of the solutions are aggressive and can give off irritating and corrosive fumes. Etching should be done in a well-ventilated room, preferably under a fume hood. The solution should be mixed and placed in a corrosion resistant tray or dish and brought to the operating temperature.
6.1.3 The volume of the bath shall be adequate, at least of the order of 11 of reagent per square decimetre of area of the test piece. In addition, the bath shall be sufficiently deep for the height of liquid above the upper face of the test piece to be at least 25 mm.
6.1.4 The specimen or specimens should be placed on some non-reactive supporl Glass rods often are placed on the bottom of the acid container and the specimens are laid directly on the rods.
6.1.5 When etching several test pieces in the same bath, ensure that there is no contact between them, avoiding an uneven and misleading etching.
6.1.6 In the case of large specimens which cannot be immersed, such as Ingot sections, swabbing might be the only practical method of macroetching. Saturate a large wad of cotton held in stainless steel or nickel tongs with the etchant and sweep over the surface of the specimen. An effort should be made to wet the entire surface as soon as possible. After the initial wetting, keep the swab saturated with solution and frequently sweep over the surface of the specimen to renew the solution. Ensure a uniform and constant distribution of the reagent over the surface. When the structure has been suitably developed, rinse the specimen, either with a swab saturated with water, or better still, by pouring water over the specimen. After rinsing with water, blow the specimen dry with compressed air.ISO 4969-2015 pdf free download.