AWS D15.2-D15.2M:2013 pdf download.Recommended Practices for the Welding of Rails and Related Rail Components for Use by Rail Vehicles
1.1 Scope. This document recommends standards for joining, repair, maintenance, inspection of rail welds, and related rail components. For the purposes of this document, rails include railroad rails, crane rails, guard rails, electrical contact rails, girder rails, and retarder rails. Classification of rails is based on the American Railway Engineering and Maintenance-of-Way Association (AREMA) specifications governing the manufacture of rails.
Related rail components include rail crossings and turnouts which further include switch points, stock rails, switch point guards, spacer blocks, connecting rods, switch rods, plates, frogs, and frog components.
The use of track components reconditioned by welding is a decision of the rail owner outside the scope of this document.
This document does not include road bed maintenance except where it affects the expected life of the repair.
Welding processes addressed in this document include shielded metal arc welding (SMAW), gas metal arc welding (GMAW), flux cored arc welding (FCAW), flash welding (FW), and thermite welding (TW). See Annex A and the Welding Handbook, Volumes 2 and 3, Ninth Edition for details on these processes.
1.2 Units of Measurement. This standard makes use of both U.S. Customary Units and the Intermational System of Units (SI). The latter are shown within brackets [ ], or in appropriate columns in tables and figures. The measurements may not be exact equivalents; therefore, each system must be used independently.
1.3 Safety. Safety and health issues and concerns are beyond the scope of this standard; some safety and health information is provided, but such issues are not fully addressed herein.
5.7.2.3 The guards of self- guarded frogs shall be rebuilt to their original dimension prior to other repairs. Enough time should be allowed between traffice movements to allow complete welding and finish grinding of the raised guard.After the guards have been repaired, the tread portion should be restored.
5.7.2.4 Immediately after completing each bead, stress relieve the bead by peening with the ball end of a two pound ball-peen hammer. The bead should be struck two to four times per inch of weld using moderate blows that produce an indentation of approximately 0.040 in [1.0 mm]. Peening should start at the crater and proceed toward the start of the weld. Do not peen the first bead layer, as this will prevent damage between the bead interface and the parent material. Do not peen the final layer, as this will to prevent blemishes in the finished surface.
6. Recommended Practices for Joining of Rails by Thermite Welding (TW)
Thermite is defined as a mixture of finely divided aluminum and iron oxide. When the aluminum and iron oxide react, the reaction is called a thermite reaction. Thermite welding is accomplished with the heat produced by the thermite reaction. Filler metal is obtained from the combination of the iron reaction product and pre-alloyed shot in the mixture.AWS D15.2-D15.2M pdf download.