LNG低温储罐用9Ni钢板焊接接头性能研究

Research on Mechanical Properties of 9Ni Steel Plate Welded Joint for LNG Cryogenic Storage Tank

以26.5 mm厚度规格9Ni钢板焊接接头为对象,研究了电弧手工焊(SMAW)、埋弧自动焊(SAW)焊接接头的拉伸、低温韧性以及硬度等性能。结果表明:常温焊缝处屈服强度较低,但在-163℃的服役温度下,焊缝处屈服强度超过650 MPa;焊接接头的韧性薄弱环节在熔合线区域;焊接接头的硬度表现为焊缝及母材低,熔合线及靠近熔合线的母材热影响区硬度高。

Taking the welded joint of 26.5 mm thickness 9Ni steel plate as an object,the tensile strength,low temperature toughness and hardness of the SMAW and SAW welded joint are studied.The results show that the yield strength of welding seam at ambient temperature is lower,while the yield strength of welding seam at-163℃service temperature exceeds 650 MPa.The weak point of welded joint ductility is in the area of the fusion line.The hardness of the welded joint is lower at the welding seam and base metal,but is higher at the fusion line and fusion line adjacent HAZ area of base metal.