ASTM D807-18,Standard Practice for Assessing the Tendency of Industrial Boiler Waters to Cause Embrittlement (USBM Embrittlement Detector Method).
ASTM D807-18 may be applied to embrittlement resistance testing of steels other than boiler plate, provided that a duplicate, unexposed specimen does not crack when bent 90° on a 2-in. (51-mm) radius.
Summary of Practice
For embrittlement cracking of the boiler metal to be possible, the boiler water must concentrate a thousand times or more in contact with the metal under high residual or applied tensile stress. In a boiler such concentration may take place in riveted seams or in annular spaces at tube ends, and the steel at such locations may be highly stressed when the boiler is constructed or may become highly stressed when it is operated.If the chemicals in the boiler water concentrate in the seams to develop an embrittling solution, cracking may occur.
Precision and Bias
Since the character of a boiler water may change with variation in the water supply or the chemical treatment of the water, any conclusions based upon the condition of the test specimens are strictly valid only with respect to the actual periods of exposure.
In as much as a personal element is involved in the operation of the detector, there is an uncertainty factor in a test that results in no cracking. Correlation of more than 800 tests made by average plant personnel indicates that the probable chance of error is no more than 5 % after 30, 60, and 90-day tests have been completed.