Over deze norm
1.1 This practice, known as the embrittlement-detector method, covers the apparatus and procedure for determining the embrittling or nonembrittling characteristics of the water in an operating boiler. The interpretation of the results shall be restricted to the limits set forth in Section 8.6.
Note 1—The embrittlement detector was designed to reproduce closely the conditions existing in an actual boiler seam. It is considered probable that the individual conditions of leakage, concentration, and stress in the boiler seam can equal those in the detector. The essential difference between the detector and the boiler is that the former is so constructed and operated that these three major factors act simultaneously, continuously, and under the most favorable circumstances to produce cracking; whereas, in the boiler the three factors are brought together only under unique circumstances. Furthermore, in the detector any cracking is produced in a small test surface that can be inspected thoroughly, while the susceptible areas in a boiler are large and can be inspected only with difficulty. In these respects the embrittlement detector provides an accelerated test of the fourth condition necessary for embrittlement, the embrittling nature of the boiler water.
Note 2—Cracks in a specimen after being subjected to this test indicate that the boiler water can cause embrittlement cracking, but not that the boiler in question necessarily has cracked or will crack.
1.2 The effectiveness of treatment to prevent cracking, as well as an indication of whether an unsafe condition exists, are shown by this practice. Such treatments are evaluated in terms of method specimen resistance to failure.
1.3 The practice 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.
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 appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
|Engelse titel||Standard Practice for Assessing the Tendency of Industrial Boiler Waters to Cause Embrittlement (USBM Embrittlement Detector Method)|