To ensure the satisfactory performance of a welded structure, the quality of the welds must be determined by adequate testing procedures. Therefore, they are proof tested under conditions that are the same or more severe than those encountered by the welded structures in the field. These tests reveal weak or defective sections that can be corrected before the materiel is released for use in the field. The tests also determine the proper welding design for ordnance equipment and forestall injury and inconvenience to personnel
13-2. TESTING OF MILITARY MATERIEL
a. Weapons can be proof tested by firing from cover with an every heavy charge too determine the safety of the welded piece.
b. Automotive materiel can be tested at high speeds over rough ground to determine its road safety.
c. Welded armor plate and other heavy structural members can be tested by gun strength fire with projectiles of various calibers to determine their strengths under shock.
d. Other similar tests are used to check the performance of complex structures; however, because the piece of materiel may consist of several types of metals welded with various filler metals, the successful operation of the entire structure requires that each weld must be able to withstand the particular load for which it is designed. For this reason, a number of physical tests have been devised to determine the strength and other characteristics of the welds used in the structure.
13-3. FIELD INSPECTION OF WELDS AND EQUIPMENT REPAIRED BY WELDING
a. General. A definite procedure for the testing of welds is not set up as a part of the normal routine of ordnance units operating under field conditions. If facilities are available, some of the physical testing methods may be instituted. In general, however, the item welded is subjected to a thorough visual examination by a qualified inspector, and if found to be satisfactory, it is then returned to the using arm or service.
b. Inspection Procedure. The finished weld should be inspected for undercut, overlap, surface checks, cracks, or other defects. Also, the degree of penetration and side wall fusion, extent of reinforcement, and size and position of the welds are important factors in the determination as to whether a welding job should be accepted or rejected, because they all reflect the qualify of the weld.
c. Destructive Tests of Experimental Welds. If special circumstances require the use of a new or novel welding procedure, new welding material, or unfamiliar apparatus, and when welding operators lack experience in their use, it is advisable to make experimental welds with scrap or unsalvageable material. These welds or welded materials must be subjected to destructive tests. The required development of procedure and familiarity with equipment can be attained in this manner.
d. Performance Tests. When materiel has been repaired by standard welding procedures, visual inspection should be sufficient to determine the efficiency of the weld. However, after the repaired item has been returned to the using arm or service, the item should be subjected to such practical tests as are necessary to prove its ability to withstand the strains and stresses of normal service. This will involve the towing or driving of mobile equipment over terrain that it is normally expected to traverse and the firing of artillery pieces to ensure that the repair will not break down under the forces of recoil. In most cases, the item can be placed in service with instructions to the using personnel to make one or more thorough inspections after the item has been in service a short time and to report signs of possible failure or unsatisfactory performance. Defective repaired parts can, in this way, be detected before serious trouble results.