This test method deals with the acceptance specifications for the ultrasonic examination of forged steel crankshafts. This practice is applicable to both solid (slab) forged and continuous grain flow crankshafts. Specimens shall be divided into three volumetric zones, namely: the major critical sections (Zone 1), which includes the heavily loaded areas of the crankpins, webs, and main bearings; the minor critical sections (Zone 2), which includes the balance of the surface areas of the main bearing and crankpin journals and adjacent fillets, flanges, and gear fit areas; and Zone 3, which includes the balance of the crankshaft, and the remaining sections of the webs. The crankshafts shall be examined after heat treatment, but before machining geometric features such as chamfers and oil holes. Acceptance zones and criteria for both types of crankshafts are discussed briefly.

1.1 This is an acceptance specification for the ultrasonic inspection of forged steel crankshafts having main bearing journals or crankpins 4 in. [100 mm] or larger in diameter.

1.2 This specification covers the testing equipment required and the test procedure to be followed, and it defines the critical and noncritical areas and limits of acceptance.

1.3 This specification is intended to cover both continuous grain flow (CGF) crankshafts for medium and high speed diesel engines as well as solid (slab) forged crankshafts for other applications.

1.4 The values stated in either inch-pound units or SI (metric) units are to be regarded separately as the standard. Within the text and tables, the SI units are shown in brackets. The values stated in each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.

1.5 Unless the order specifies the applicable “M” specification designation, the inch-pound units shall be used.

1.6 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.