AWS D15.2/D15.2M pdf free download
AWS D15.2/D15.2M pdf free download.Recommended Practices for the Welding of Rails and Related Rail Components for Use by Rail Vehicles.
4. Rail, Rail Components Manufactured from Rail, and Their Repair
It is essential to identify the rail or rail base metal material to attain optimal results in selecting the welding procedure.
4.1 Specific Items. These recommendations apply to, but are not limited to. the items listed in the scope of this document.
4,2 Welding and Joining Processes. Processes include shielded metal arc welding (SMAW). gas metal are welding (GMAW), flux cored arc welding (FCAW), flash welding (FW), and thermite welding (TW).
4.3 Railroad Rail Welding
4.3.1 Railroad Rail Grades
4.3.1.1 Standard Carbon steel rail has a minimum hardness of 248 BHN.
4.3.1.2 Premium carbon steel rail has a nominal hardness exceeding 341 BHN. This hardness may be the result of alloy composition (nonheat treated) or heat treatment process. Heat treated rail and other variations may require special welding procedures as recommended by ihe rail manufacturer or filler metal producer, or both.
4.3.1.3 Electrical contact rails are low carbon steel rails without hardness requirements.
4.3.2 Procedure Requirements for Arc Welding of Carbon Steel Rail
4.3.2.1 Preheating the weld area to a minimum of 700° F 1370°C1 not to exceed 1(XX)°F 1538 °CJ as measured immediately before welding is recommended to equalize temperature in the workpiece and to reduce the cooling rate.
4.3.2.2 Interpass temperature shall be within the same range as the preheat temperature to maintain temperature in the workpiece.
4.3.2.3 Weld deposit should have a nominal surface hardness compatible with the existing base metal to eliminate deformation or cracking of the weld.
4.3.2.4 Postweld heat treatment is recommended between 1000°F to 1100°F 1538°C to 593°CJ. but is not required unless dictated by past experience or by approved railroad welding procedures.
4.3.3 Procedure Requirements for Arc Welding of Premium Carbon Steel Rail
4.3.3.1 Remove grease, oil, paint, dirt, and other deleterious matter that will adversely affect weld quality. Inspect the entire area for cracks and other defects. Liquid penetrant testing may be used to locate and define the cracks.
4.3.3.2 A preheat temperature of a minimum of 7(X)° F 1370°CI not to exceed l(XX)°F 1538 °C1 is recommended for alloy steel rail.
4.4 Repair of Battered Rail Ends and Wheel Burns (Carbon Steel or Premium Carbon Steel Rail)
4.4.1 Carbon steel or premium carbon steel rail may be repaired using an arc welding process selected from 4.2 and Table 4.1.
4.4.3.6 Provisions must be made to minimize distortion of the weld area.
4.4.3.7 All weld craters should be tilled by reversing direction and welding back into the bead before breaking the arc.
4.4.3.8 Arc strikes shall not be permitted outside the preheated repair area. Accidental arc strikes outside the repair area shall be repaired in accordance with the provisions of 4.4.2.2.
4.4.4 Finish Grinding
4.4.4.1 Welds should be finish ground according to approved procedures on the same work day the rail is welded to minimize impact loading and prevent weld deformation.
4.4.4.2 Finish surface of the weld should be smooth and uniform with the existing rail contour.
4.5 Repair of Rail-Type Switch Points and Switch Point Protectors
4.5.1 Weld repair of austenitic manganese steel switch points is not recommended because the heat input is difticult to control properly to limit distortion.
4.5.2 Carbon steel and premium carbon steel rail components may be welded by the arc welding processes shown in Table 4.1.
4.5.3 Visually inspect the switch point or switch point protector to determine the repairability in accordance with the rail owner’s policy.AWS D15.2/D15.2M pdf download.
