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

摘要： 针对可焊接超高强度Q690DR钢板，研制了配套手工焊条CHE807QR，并开展了焊接性能研究。通过斜Y型坡口焊接裂纹试验可知，Q690DR钢板在不预热时冷裂纹敏感性强，预热温度不小于100℃时对冷裂纹不敏感。基于CHE807QR的焊接接头，在150～180℃预热温度下焊态、热处理态的焊接接头，均满足抗拉强度不小于800 MPa、屈服强度不小于690 MPa的要求，-40℃冲击功在110 J左右，其综合力学性能和低温冲击韧性与母材有较好的匹配性。基于低应变速率缺口拉伸测试，测得焊材CHE807QR的焊接接头在10 MPa氢气下与同压力氮气下的相对抗拉强度约为78.08%，在10 MPa氢气环境中，CHE807QR焊接接头的裂纹扩展速率是同压力氮气环境中的13.5倍左右。CHE807QR焊接接头在10 MPa氮气、10 MPa氢气下的断裂韧性分别约为252.6113.1 MPa/m^0.5。CHE807QR焊材与母材性能高度匹配，满足技术条件要求，可用于高压储氢容器后续试验罐和示范工程项目的建造。

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