ASNT

Figure 17 William Coolidge, inventor of X-ray tube: (a) posing with 1 MeV tube; (b) X-ray tube. (a) (b)

back to the time of World War I. The early work in the United Kingdom, particularly the armament- related X-ray nondestructive testing work of V.E. Pullin, is described in detail by R. Halmshaw (Halmshaw 1988). An excellent description of early work in Germany shows many examples of radiographic nondestructive testing, including field test systems dating from the 1920s (Krüger and Weeber 1983). A recent summary of X-ray history is given in the X-ray centennial issue of Insight, including articles about X-ray development in the United Kingdom and in Germany (British Institute of Non Destructive Testing 1995). Early work in the United States is documented in patents (Jackson et al. 1948; McMaster and Wenk 1951). Despite these early efforts and many demonstrations of X-rays for material examination (Coolidge 1916), radiographic nondestructive testing did not become important commercially until World War II. In the United States, workers in nondestructive testing cite the early work of Horace Lester (Figure 18) at the Watertown Arsenal (Figure 19) as laying the groundwork for the present use of radiography (Lester 1922; Lester 1923). Lester’s work was significant because it clearly demonstrated that X-rays could be used to locate internal discontinuities in castings, welds, and other metal forms and that these discontinuities could lead to premature failure. Lester’s contributions were also important because

of his preeminent position in the metallurgical field (Wenk 1969; Norton 1986). However, there was significant work done in the United States in radiographic nondestructive testing even before Lester’s landmark research. An excellent review of early X-ray nondestructive testing work was given in a 1929 paper prepared for ASM International, when the organization was called the American Society for Steel Treating (Fink and Archer 1929). The paper cites 108 references, with 46 of these dating during the period 1915 to 1921. Prominent among the early citations is the work of Wheeler R. Davey, who did research on radiographic nondestructive testing at the General Electric Research Laboratory (1914 to 1926) and later at

Figure 18 Horace Lester.

CHAPTER 1

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Part 2