TEST PIECE AND METHOD FOR DELAYED FRACTURE CHARACTERISTIC EVALUATION OF ULTRA-HIGH STRENGTH SURFACE TREATED STEEL PLATE

摘要

PROBLEM TO BE SOLVED: To provide a test piece for delayed fracture characteristic evaluation of an ultra-high strength surface treated steel plate capable of contributing to the accurate evaluation of delayed fracture characteristics of the ultra-high strength surface treated steel plate whose tensile strength is 1180 MPa or more.SOLUTION: An end face surface of a test piece 1 is processed into a surface having surface roughness of 6.3 m or less in an arithmetic average Ra specified in JISB0601-2001, and the test piece 1 has a synthetic resin coating film 5 formed on the end face surface.