ASTM E2905/E2905M-13 pdf free download.Standard Practice for Examination of Mill and Kiln Girth Gear Teeth—Electromagnetic Methods.
ASTM E2905/E2905M-13 describes a two-part procedure for electromagnetic evaluation on gear teeth on mill and kiln gear drives and pinions. The first part of this practice details the ability to detect 100 % of surface-breaking discontinuities only in the addendum, dedendum, and root area on both the drive side and non-drive side of the gear tooth using an eddy current array. The second part of the examination is to size or measure accurately the length and depth of any cracks found in these areas using electromagnetic methods. No other practice addresses the use of electromagnetic methods for the detection and sizing of surface-breaking discontinuities on mill and kiln ring gear teeth.
4. Summary of Practice
4.1 Gear-Cleaning Procedure-Typically, mill operations does the cleaning or supervises the cleaning Mill maintenance removes the guards for access to the gear. Nondestructive evaluation (NDE) mill girth gear examinations are provided for maintenance. Visual interpretation is also a common method used to analyze gear teeth condition, such as contact patterns and wear patterns. For visual inspection, a cleaned gear is mandatory. Another reason for a cleaned gear tooth is that it is very hard for the ECA probe to maintain the geometry of a gear tooth that is covered with lubricant, especially if the lubricant is asphaltic-based or synthetic. If asphaltic or sythetic lubrication is used, refer to Appendix X2 for cleaning procedures.
10. Procedure
10.1 Preparing the Gear before Examination-Ensure the addendum. dedendum. and root on both the drive side and the non-drive side of the gear teeth are clean. If the lubrication used is an oil bath type, then the probe will glide along the gear tooth surface with ease and additional cleaning may not be required. If an asphaltic-based or synthetic lubricant is used, refer to Appendix X2.