NMWR-9-2815-220 Overhaul Manual for M60 M88 Engine AVDS-1790-2CA, AVDS-1790-2DA, AVDS-1790-2DR Download
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NMWR 9-2815-220 GENERAL MAINTENANCE, OVERHAUL, AND REPAIR PROCEDURES—Continued 0005 00 SPECIAL PROCESSES - Continued (4) Cast aluminum parts may be welded in approved areas to add sufficient finish stock, repair cracks, sandholes, etc., per AWS D17.1, using welding rod AWS-A5.10/A5.10M with exception of those prohibited by TACOM, DRSTA-MB. (5) Steels parts may be welded in approved areas to add sufficient finish stock, repair cracks, etc., per ASTM-A488/A488M, using electrode conforming AWS-D1.1/D1.1M. (6) For static applications only, (when approved by TACOM, DRSTA-MB), spray metallizing per AWS- C2.25/C2.25M, may be used to repair steel or aluminum parts. (7) Damaged threaded fasteners may be repaired by installing helicoil inserts, etc., as permitted by TACOM, DRSTA-MB (8) Peening, rolling, etc., may be used with permission from TACOM, DRSTA-MB. 8. Reclamation instructions are listed in each individual work package. DIAGNOSTIC AND AUTOMATED TEST EQUIPMENT 1. Magnetic Particle Inspection. a. General. Magnetic particle inspection is a rapid nondestructive means of detecting faults in parts made of ferromagnetic materials. These faults may have been inherent in the metal, put into the parts during fabrication or processing, or formed during actual use of the parts. They may be at or near the surface and may be shallow or deep. If magnetic particle inspection is used correctly, both surface and subsurface faults will be revealed. b. Personnel. All magnetic particle inspection personnel shall be qualified in accordance with NAS410(2). c. Magnetizing Apparatus, The magnetic particle inspection equipment shall conform to the requirements of ASTM E-1444. The equipment shall be maintained in such a manner as to ensure uniform, controlled inspection operations. d. Types of Magnetizing Current. (1) Direct current obtained by passing three-phase alternating current through special rectifiers is the most commonly used in wet horizontal units for any general magnetic particle inspection need. (2) Rectified single-phase alternating current is most suitable for subsurface defects, using dry particles (castings, welds, etc.). (3) Alternating current is suitable for detecting surface defects only because penetration is very shallow. Alternating current is a reliable method of detecting fatigue cracks. 0005 00-13 Change 1