Regular Article

Investigation of stress corrosion cracking behavior of L360QS in different groove angles by electrochemical and SSRT method

School of New Energy and Materials, Southwest Petroleum University, Chengdu 610500, China

^* e-mail: 380056676@qq.com

Received: 2 March 2022
Accepted: 4 August 2022

Abstract

The effect of two different groove angles on stress corrosion cracking (SCC) sensitivity of welded joints was investigated by electrochemical and SSRT methods, and the fracture surface of tensile specimens was observed by SEM. The electrochemical results show that the corrosion resistance of HAZ region increases with the increase of welding groove angle, while the corrosion resistance of weld region decreases with the increase of welding groove angle. The results of SSRT of the welded joint show that, under the condition of no applied potential, under different welding groove angles (8°/15°), The maximum tensile strength is 546.08 MPa/560.64 MPa, the maximum fracture life is 44.6 h/46.8 h, the maximum elongation after fracture is 9.40%/9.73%, and the maximum reduction of area is 63.53%/65.14%. With the negative increase of applied potential, the SCC sensitivity of welded joint also shows an obvious increasing trend. The fracture morphology of the SSRT tensile test shows that with the negative increase of applied potential, the fracture changes from dimple-like ductile fracture to typical brittle fracture, and obvious stress corrosion fracture occurs.