ASTM E208-17e1,Standard Test Method for Conducting Drop-Weight Test to Determine Nil-Ductility Transition Temperature of Ferritic Steels.
ASTM E208-17e1 covers the determination of the nil-ductility transition (NDT) temperature of ferritic steels, 5/8 in. (15.9 mm) and thicker.
ASTM E208-17e1 may be used whenever the inquiry, contract, order, or specification states that the steels are subject to fracture toughness requirements as determined by the drop-weight test.
This drop-weight test was developed at the Naval Research Laboratory in 1952 and has been used extensively to investigate the conditions required for initiation of brittle fractures in structural steels Drop-weight test facilities have been established at sevcral Naval activitics, research institutions, and industrial organizations in this country and abroad. The method is used for specification purposes by industrial organizations and is referenced in several ASTM specifications and the ASME Boiler and Pressure Vessel Code. This procedure was prepared to ensure that tests conducted at all locations would have a common meaning. This test method was originally published as Department of the Navy document NAVSHlPS-250-634-3.
4. Summary of Test Method
4.1 The drop-weight test employs simple beam specimens specially prepared to create a material crack in their tensile surfaces at an early time interval of the test. The test is conducted by subjecting cach of a series (generally four to eight)of specimens of a given matcrial to a single impact load at a sequence of selected temperatures to determine the maximum temperature at which a specimen breaks. The impact load is provided by a guided, frcefalling weight with an energy of 250 to 1400 ft lbf (340 to 1900 J) depending on the yiel strength of the steel to be tested. The specimens are prevented by a stop from deflecting more than a few tenths of an inch.