SECTION I. PURPOSE

TB 9-2510-242-40

SECTION I. PURPOSE

This appendix provides instructions for performing weld repairs to the M747 trailer. Section II covers repairs to the trailer

frame and gives instructions for welding T-1 steel. Section m covers repairs to the trailer ramps and gives instructions

for welding aluminum.

1.1 INTRODUCTION

Section II of this appendix provides a review of weld procedures to be used in the repair of M747 trailer frames. The

M747 frame is fabricated from T-1 Steel, a high strength, quenched and tempered, structural alloy steel. T-1 steel frame

members can be welded satisfactorily providing that proper procedures are followed.

The following are the most critical elements of successful T-1 steel repair welding: (1) use of the correct electrodes, (2)

appropriate heating, and (3) proper welding techniques. Arc-welding processes, including shielded metal-arc, gas metal-

arc and gas tungsten-arc, are acceptable methods for welding T-1 steel.

Section m of this appendix provides a review of weld procedures to be used in the repair of the M747 trailer ramp. The

M747 ramp is fabricated from 6061 T6 aluminum alloy in accordance with QQ-A-200/8, QQ-A-200/11, and QQ-A-200/20.

This material may be welded, but proper welding practices must be followed to prevent distortion and loss of strength in

the base metal surrounding the weld area. Aluminum weld repairs should be made using the correct electrodes, filler

metal and appropriate heat input. Gas Metal-arc and gas Tungsten-arc welding are the preferred welding processes for

welding 6061 T6 aluminum.

2.1 SCOPE

The weld procedures in Section II apply to maintenance and repair welding of the M747 trailer frame and pertain to

damage such as weld/joint failures, cracks/tears in base metal members, and frame reinforcement. This appendix

addresses T-1 material properties, cutting and preparing frame members for welding, electrode selection, preheating and

heat input, welding techniques and post-weld inspection. The weld procedures in Section m apply to maintenance and

repair welding of the M747 aluminum ramp frame and pertain to damage such as cracks/tears in the base metal,

weld/joint failures, and frame reinforcement. This appendix addresses 6061 T6 aluminum characteristics, preparation of

ramp frame members for welding, electrode selection, preheating and heat input, welding techniques, and post-weld

inspection. Arc-welding processes, preferably gas metal-arc and gas tungsten-arc, are acceptable methods for welding

6061 T6 aluminum.

E-3