Article Article
Assessing Mottled Indications When Digitally Radiographing Austenitic Stainless Steel Welds

When radiographing an austenitic stainless steel weld with an appreciable weld deposit size, selecting a low radiographic kilovoltage (keV) can contribute to producing a radiographic indication that is not an imperfection. The contributors to this mottled condition are both radiographical and metallurgical. Electrons from low keV can diffract or absorb when penetrating through the dendritic grain structure of a weld. The increase in keV, or using gamma ray–equivalent isotopes, produces a marked change in electron output and penetration in material.



ASM, 1976, Metals Handbook, 8th edition, Vol. 11: Nondestructive Inspection and Quality Control, American Society of Metals, Materials Park, OH, p. 144

ASM, 1983, Metals Handbook, 9th edition, Vol. 6: Principles of Joining Metallurgy, American Society of Metals, Materials Park, OH, pp. 22–49

ASME, 2007a, Boiler and Pressure Vessel Code; Section III, Construction of Nuclear Facility Components, Subsection NB Class 1 Components, American Society of Mechanical Engineers, New York, NY

ASME, 2007b, Boiler and Pressure Vessel Code, Section V: Nondestructive Examination, Mandatory Appendix I, Terms and Definitions, American Society of Mechanical Engineers, New York, NY

ASNT, 1985, Nondestructive Testing Handbook, Vol. 3: Radiography and Radiation Testing, second edition, American Society for Nondestructive Testing, Columbus, OH, pp. 211–212 

EPRI, 2003, Ultrasonic Examination Technology - Level II Practical Specific Module 2PS, Electric Power Research Institute, pp. 9–13

Kodak, 1980, Radiography in Modern Industry, fourth edition, Eastman Kodak Co., Rochester, NY, pp. 31, 44, 58

Mintern, R.A., and Chaston, J.C., 1959, “Gamma Radiography with Iridium 192: Advantages in the Nondestructive Testing of Castings and Welded Structures,” Platinum Metals Review, Vol. 3, No. 1, pp. 12–16

NDT Resource Center, 2021, “Radiograph Interpretation – Welds,”, accessed 23 November 2021

Watanabe, T., T. Sofue, Y. Saeki, and H. Mizukoshi, 1988, “Effects of Segregation on Mottling Seen on Radiographs of Stainless Steel Weldments,” Welding International, Vol. 2, No. 3, pp. 224–228,


Usage Shares
Total Views
18 Page Views
Total Shares
0 Tweets
0 PDF Downloads
0 Facebook Shares
Total Usage