Welding explosive

Nondestructive Testing. Nondestmctive inspection of an explosion-welded composite is almost totally restricted to ultrasonic and visual inspection. Radiographic inspection is appHcable only to special types of composites consisting of two metals having a significant mismatch in density and a large wave pattern in the bond interface (see Nondestructive evaluation). 

Ultrasonics. The most widely used nondestmctive test method for explosion-welded composites is ultrasonic inspection. Pulse-echo procedures (ASTM A435) are appHcable for inspection of explosion-welded composites used in pressure appHcations. 

The clad plate is x-rayed perpendicular from the steel side and the film contacts the aluminum. Radiography reveals the wavy interface of explosion-welded, aluminum-clad steel as uniformly spaced, light and dark lines with a frequency of one to three lines per centimeter. The waves characterize a strong and ductile transition joint and represent the acceptable condition. The clad is interpreted to be nonbonded when the x-ray shows complete loss of the wavy interface (see X-ray technology). 

Destructive Testing. Destmctive testing is used to determine the strength of the weld and the effect of the explosion-welding process on the parent metals. Standard testing techniques can be utilized on many composites however, nonstandard or specially designed tests often are required to provide meaningful data for specific appHcations. 

Chisel. Chisel testing is a quick, qualitative technique that is widely used to determine the soundness of explosion-welded metal interfaces. A chisel is driven into and along the weld interface, and the abiUty of the interface to resist the separating force of the chisel provides an excellent quaUtative measure of weld ductihty and strength. 

Hardness, Impact Strength. Microhardness profiles on sections from explosion-bonded materials show the effect of strain hardening on the metals in the composite (see Hardness). Figure 8 Ulustrates the effect of cladding a strain-hardening austenitic stainless steel to a carbon steel. The austenitic stainless steel is hardened adjacent to the weld interface by explosion welding, whereas the carbon steel is not hardened to a great extent. 

Ma.rine. In the presence of an electrolyte, eg, seawater, aluminum and steel form a galvanic cell and corrosion takes place at the interface. Because the aluminum superstmcture is bolted to the steel bulkhead in a lap joint, crevice corrosion is masked and may remain uimoticed until replacement is required. By using transition-joint strips cut from explosion-welded clads, the corrosion problem can be eliminated. Because the transition is metaHurgicaHy bonded, there is no crevice in which the electrolyte can act and galvanic action caimot take place. Steel corrosion is confined to external surfaces where it can be detected easily and corrected by simple wire bmshing and painting. 

Explosion-welded constmction has equivalent or better properties than the more compHcated riveted systems. Peripheral benefits include weight savings and perfect electrical grounding. In addition to lower initial installation costs, the welded system requires tittle or no maintenance and, therefore minimizes life-cycle costs. Applications of stmctural transition joints include aluminum superstmctures that are welded to decks of naval vessels and commercial ships as illustrated in Figure 11. 

J. M. Stone, paper presented at Select Conference on Explosive Welding, Hove, U.K., Sept. 1968, pp. 29—34. 

The anodes for internal protection of containers and tanks are frequently fixed by screws because of the danger of explosion, welding or brazing is not allowed. 

From the practical point of view, extreme interest was attached to explosions in soils, rocks, and metals. The findings have been applied in the use of expls for rock excavation deep drilling, explosion forming, explosion welding, and so on... 

Explosive extrusion has been investigated by the Air Materiel Command of the US Air Force but it is not described in Ref 7 Explosive welding, mentioned in Ref 7, pp 3 5 is described as a separate item Explosive forming is used for manuf parts which cannot be made by other methods (See also Explosive Metallurgy Explosive Metalworking, High-Velocity Explosive Press and Explosive Welding)... 

Explosive Press" and Explosive Welding (See also Explosive Metalworking)... 

The explosively welded joints are less than one-half inch in width and apparently have no long-length limitation. The ribbon explosive" developed in this study contains very small quantities of expl (RDX) encased in a flexible thin lead sheath and initiated with a blasting cap... 

Refs 1) V-Philipchuk, "Explosive Welding , Aeronautical System Division (ASD) Tech Rept 61-124 (1961), Wright-Patterson Air Force Base, Ohio 2) D.E.Davenport G.E. Duvall "Explosive Welding , American Society of Tool and Manufacturing Engineers (ASTME) Tech Paper SP 60-161 (1961), Detroit, Michigan 3) H.J. Addison et al,... 

Explosive Welding of Cylindrical Shapes , Frankford Arsenal, Philadelphia May 1969, 18pp, Order as AD-694359 from National Technical Information Service, P.O.Box 1553, Ravensworth, Virginia 22151 4) J.G.Et-... 

High bulk-densiry NGu and recrystn of NGu from aq soln contg a little HAc and a little of a deriv of NGu such as hyarazone, hyarazide, amide, amine, sulfonamide, sulfate) 20a) Cond-ChemDicr (1961), 805-R (NGu) 21) L.D. Sadwin, Science 143(3611), 1164, 1169(1964) CA 60, 14188(1964) (Explosive welding with NGu)... 

Although stainless steel (SS) remains the most used cladding material, exotic materials such as titanium, zirconium or tantalum are finding increasing applications. Apart from plate-to-plate and tube-to-tube-plate, there are many other applications for explosive welding which are listed below. 

I. Berman J.W. Schroeder, Eds, Explosive Welding, Forming, Plugging, and Compaction , The American Society of Mechanical Engineers, New York, NY (1980)... 

Some particular processes can require very high pressures for special applications (i.e. in explosive welding and plating), but pressures between 100 and 1000 bar can be found easily in different industrial processes. Typical examples are the synthesis of ammonia, the synthesis of methanol and the production of low-density polyethylene, but also analytical techniques as high-pressure liquid chromatography. Other important implications are for the storage and transportation of fluids and enhanced oil recovery. 

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