2. Dye Penetrant Inspection - This is an easily applied process which indicates cracks or surface conditions. The process is relatively inexpensive, but does not produce a permanent record except by normal photography. 2. Clean and grind the entire repair area to remove all rust, grease, oils, paint, and any other foreign materials likely to contaminate the weld. 3. Air arc out all cracks in the form of a “V” shape. The depth of the “V” is determined by the depth of the crack; the width to depth ratio should be approximately 1.25:1, and never less than 1:1. Cracks through the parent material will require a “V” with a root width slightly wider than the thick- ness of the 0.25 in.
(6 mm) backup strip material. Backup strips are required for all cracks which have gone through the parent metal and cannot be welded from both sides. 3. Fluorescent Penetrant Inspection - Similar to dye penetrant inspection. This process uses a black (ultraviolet) light for increased efficiency and accuracy. 4. Magnetic Particle Inspection - This process requires special equipment that is usually more costly than the dye penetrant inspections. This process does not provide a permanent record except by normal photography. 4. Use dye penetrant to insure cracks are completely removed. 5. Ultrasonic Inspection - This is a popular method of examining weld discontinuities.
Specialized equipment and operator certification is required. With some equipment, printed data of the test can be created for a permanent record. Operator records with equipment settings and test results are also, normally recorded. 5. After air arcing and inspections (steps 3 & 4), all areas cut by the air arc should be cleaned thor- oughly with a grinder to remove all possible car- bon deposits and dye penetrant. 6. Fill gouges with weld and grind all surfaces smooth to avoid defects in new welds. 6. X-Ray Inspection - This process provides a view of the weld and base materials but it is highly spe- cialized.
This procedure provides a permanent visual record, but is more expensive than most other inspection techniques. 7. Grind all surfaces to be welded so they are free of slag, rust, or other foreign material. 8. Preheat the entire weld joint area until the sur- rounding surface area reaches 300° F (150° C) at a distance of 3 in. (7.6 cm) from all areas to be welded. RECORDS Record keeping of welding work may be of value if per- sonnel and job conditions change frequently. Forms and recording codes are provided in several welding books, and using a systematic approach will help to provide continuity of welding work done.
These records, along with photographs of the area before, during, and after repairs, can be of help when similar jobs arise, and must be accomplished by a different welder at a different location. The Service Department at Komatsu Mining Systems, Inc., Peoria Operations, should be provided with reports and photographs whenever welding repairs are made on Komatsu Trucks. 9. All welds are to be made with approved consum- ables only. The SMAW (Stick) welding rod must be used within four hours after being removed from a new sealed container or from a 125° F (32° C) minimum drying oven. Any rod that exceeds this exposure time must be re-dried for one hour at 800° F (427° C) before being used.
Keep all weld starts and stops to a minimum. 10. When welding is complete, immediately (before weldment cools) post-heat welded area to 300° F (150° C). Maintain temperature for 15 minutes, and allow to cool slowly. 11. Grind, as necessary, using 36 or finer grit grinding material. Grinding should be parallel to the direc- tion of primary stress, when possible. ANNEX A The following are general repair procedures which should be used for all frame repair and rework. 12. Hammer peen welds as outlined in ANNEX B. Repaired area should be relatively smooth and free of rough areas which may lead to stresses. 1.
The repair or rework area must be protected from wind and moisture during the entire procedure. Welding should be done at an ambient tempera- ture of 50° F (10° C) or above. 13. Inspect repaired areas for surface defects using magnetic particle inspection procedures or dye penetrant method. FAM0403 930E FIELD ASSEMBLY MANUAL Page 4-3 Field Welding Procedures