The Effects of OD Curvature and Sample Flattening on Transverse Charpy V-Notch Impact Toughness of High Strength Steel Tubular Products
SourceWith the inclusion of transverse impact toughness requirements in the American Petroleum Institute (API) specifications as well as various companies' specifications, the need arose for evaluating the effects of OD curvature and sample flattening on transverse Charpy V-Notch toughness of high strength steel tubular products. The alloy steels evaluated in this study were AISI 4130 and a modification, 4130M7. Charpy impact tests were conducted on specimens having various amounts of OD curvature and on sample flattening to determine the degree of influence of these effects. Tapering the specimens by as much as 75% or this much OD curvature did not have a significant effect on the CVN energy. Flattening of the tubes before testing reduced the CVN energy by about 4%. The factors derived from this study allow for adjustments on the test results of non-standard specimens so that a correlation can be made to standard Charpy V-Notch results.