Root Cracking Modes in Restraint Cracking Test of High Strength Steel Based on AE Technique and Fractography(Materials, Metallurgy, Weldability)

概要

論文の詳細を見る
Restraint cracking tests were applied against weldable high strength steels whose ultimate strengths are 80 and 90kg/mm^2 class. Shielded metal-arc welding was done in Y-, y- or single bevel groove in the test specimens, and AE linear source location technique along the weld line was started immediately after the welding and continued for 48hrs. Cracked surface was studied in detail with SEM ater the test. Consequently, combination of AE technique and fracto-graphy revealed that there is distinct difference in root cracking mode in relation to whether the cracking mainly passed through heat-affected zone or weld metal. The root cracking occurred in heat-affected zone has a tendency to grow alongg the weld line close to the bottom of weld bead instead of upward growth toward the surface of weld bead. On the other hand, the root cracking occurred in weld metal has a tendency to grow toward the surface of weld bead due to anisotropy of columnar crystal.
大阪大学の論文