FRACTURE TOUGHNESS EVALUATION FOR WELDED JOINTS OF HIGH STRENGTH STEEL THROUGH CTOD TEST

This paper presents the method and procedure of CTOD test which are used for the toughness evaluation for welded joints. Two types of high strength steel (E38 and E43) are chosen as the object of fracture toughness evaluation. The contents of CTOD test include three-point crack tip open displacement (CTOD) bending tests for base metal (BM) specimens, weld position (WP) specimens and heat-affected zone (HAZ) specimens of the high strength steel, considering different thickness of steel plate and different test temperature (-20 degrees C and 20 degrees C). The CTOD test can achieve the P-V curves of samples, and the CTOD values are calculated. On the basis of the above work, the results of toughness evaluation are obtained. Meanwhile, some factors which affect the toughness of high strength steel are discussed in this paper, such as thickness of steel plate and test temperature, and many valuable conclusions are achieved.