关键词: font-family:-apple-system, blinkmacsystemfont, ", font-size:14px, background-color:#FFFFFF, ">焊条, Q690DR钢板, 焊接接头, 冲击功, 氢脆敏感性, 裂纹扩展速率, 断裂韧性

Abstract: For the ultra-high-strength weldable steel plate Q690DR, a matching manual welding rod CHE807QR has been developed, and welding performance research has been carried out. Through the oblique Y-shaped groove welding crack test, it is known that the Q690DR steel plate has a strong sensitivity to cold cracks without preheating, and it is insensitive to cold cracks when the preheating temperature is not less than 100°C. Based on the welding joint of CHE807QR, at a preheating temperature of 150-180°C, both the as-welded and heat-treated welding joints meet the requirements of a tensile strength of not less than 800 MPa and a yield strength of not less than 690 MPa. The impact energy at -40°C is about 110 J, and its comprehensive mechanical properties and low-temperature impact toughness are well matched with the base material. Based on the low strain rate notch tensile test, the relative tensile strength of the welding joint of CHE807QR under 10 MPa hydrogen is about 78.08% of that under the same pressure nitrogen. In the 10 MPa hydrogen environment, the crack propagation rate of the CHE807QR welding joint is about 13.5 times that in the same pressure nitrogen environment. The fracture toughness of the CHE807QR welding joint under 10 MPa nitrogen and 10 MPa hydrogen is about 252.6113.1 MPa/m^0.5, respectively. The performance of CHE807QR welding material is highly matched with the base material and meets the technical requirements, which can be used for the construction of subsequent test tanks and demonstration projects for high-pressure hydrogen storage vessels.

Key words: font-family:-apple-system, blinkmacsystemfont, ", font-size:14px, background-color:#FFFFFF, ">welding rod, Q690DR, joint, impact energy, hydrogen embrittlement sensitivity, crack propagation rate, fracture toughness