WELD QUALITY 1. Each weld must be homogeneous with low poros- ity, and free from cracks or slag inclusions. Control of the welding area environment is essential for producing proper welds. Essentially, five areas require attention and control. 2. Each weld must have complete fusion between the base metal and weld metal added by the elec- trode. 1. Air Movement - Air movement caused by wind, drafts, or blowers should be avoided, especially when a shielding gas is being used as part of the welding process. 3. All welds must be reasonably smooth without excessive deformity. All craters must be filled. No cracks are permitted. 4.
The toe of a weld to a high stress member must have smooth transition. Excessive convexity in multi-pass fillet welds is undesirable. Excessive convexity produces high residual stress in the throat of the weld, and is not permitted. 2. Low Ambient Temperature - Welding should not be done at temperatures below 10°C (50°F). For certain low temperature conditions, preheating of the work may be necessary before welds can be made. Refer to Annex A. 3. Weld Cooling - Provisions should be made to protect the weld from a rapid cooling rate. Heat retardation may be accomplished through the use of heat lamps, torches, insulating blankets, etc.
Certain materials may require post heat also as part of the welding procedure. 5. Undercut in excess of 0.03 in. (0.76 mm) on criti- cal welds must be reworked by the application of a covering weld pass. It is important that the cov- ering weld pass blend with the existing weld. 6. When welding in the vertical position, always weld using the vertical up technique. Large wash weld weaves should not be used when welding on truck frames. Properly applied multiple pass welding is the required procedure on truck frames. 4. Moisture - Moisture on the steel surfaces to be welded must be removed before attempting to make welds.
Electrodes must be stored in sealed containers until needed, and then must be kept in a warming oven at the work location until used to prevent any moisture absorption which might affect weld quality. 7. Slag is to be removed from all weld beads, and must be completely removed before each pass in a multiple pass procedure. It is also required that all slag is removed and tie in all areas. Grind all welds where a weld crosses or intersects with another weld. 5. Foreign Materials - Any foreign substances such as dirt, paint, oil, rust, scale, carbon deposits from cutting must be removed prior to making any welds.
All surfaces to be welded should be cleaned with a grinder to insure all foreign materi- als have been removed. MATERIALS, CONTROLS AND PRECAUTIONS The steel used in the fabrication of KMS trucks and loaders is of high strength low alloy (HSLA) material of different grades. The standard dump body main plates are made from abrasion resistant materials. These materials offer themselves very well to welding during fabrication, and repair. WELD INSPECTION All welding repairs are subject to inspection by a KMS appointed inspector or laboratory to insure quality. After the weld has been made it can be inspected by a number of non-destructive evaluation techniques.
The inspections can include any of the methods listed below. All assembly welds and weld repairs that are deemed unacceptable by the inspector must be cor- rected at no additional cost to KMS. All weld repairs are also subject to additional inspection. The welding consumables are often supplied by the KMS Truck and Loader division with the new equip- ment as part of the field welding / assembly package. For field welding and repairs, the APPROVED consum- ables as detailed, should be procured from a local, reli- able supplier. Other highly specialized welding consumables are available but have limited use on KMS structural components. Approval is required from your Area Service Manager. 1.
Visual Inspection - This is the process of looking for potential defects such as undersized welds that can be checked with weld gauges. Defects include surface cracks, surface porosity, craters, and undercuts. Other highly specialized welding materials are avail- able, but have limited use on KMS products. Page 4-2 930E FIELD ASSEMBLY MANUAL FAM0403 Field Welding Procedures