TY - JOUR PY - 2022// TI - Research on stress corrosion crack failure of MIG joints on aluminum alloy of high-speed trains JO - China safety science journal (CSSJ) A1 - Lin, S. A1 - Han, X. A1 - Li, G. A1 - Wang, P. A1 - Zhao, C. A1 - Yang, Z. SP - 115 EP - 122 VL - 32 IS - 6 N2 - In order to improve service safety of high-speed trains and explore stress corrosion cracking fracture mechanism of welded joints, microstructure, mechanical properties, and stress corrosion cracking properties of MIG welding joints of 6005A aluminum alloy were investigated by adopting optical microscopy, transmission electron microscope (TEM), scanning electron microscope (SEM), hardness test, tensile test, constant stress corrosion load test and so on. The results show that under the effect of welding heat, intragranular precipitates is coarsened and redissolved in heat affected zone (HAZ), and precipitation free zone (PFZ) is widened at grain boundary. Hardness distribution of the joints is " W" type, with minimal-hardness point located in HAZ zone, and MIG joints also fracture at HAZ zone in room temperature tensile test and constant load stress corrosion test. Along with the increase of loading stress, stress corrosion cracking sensitivity will increase, and intergranular stress corrosion cracking failure fracture will accelerate. And average fracture time of the joints reaches about 42 h under high load stress (0. 9 Rp0. 2). © 2022 China Safety Science Journal. All rights reserved.
Language: zh
LA - zh SN - 1003-3033 UR - http://dx.doi.org/10.16265/j.cnki.issn1003-3033.2022.06.2061 ID - ref1 ER -