海洋平台用EH36厚钢板焊接接头的组织性能分析

摘要

In accordance with the requirements of EN 10225-2009 appendix E Standard, the EH36 thick steel plate with 100 mm thickness for offshore platforms was welded by submerge-arc welding technology with 50 kJ/cm high heat input. The microstructure and properties of the weld joint were analyzed. The results showed that either welded or heat treated after welding, the hardness HV10 of the weld joint of EH36 thick steel plate ≤ 280, tensile strength ≥ 510 MPa, the mean value of absorbed-in-fracture energy at-40℃≥50 J, the surface microstructure mainly are coarse lath bainite+a small amount of granular bainite and the core structure is fine ferrite+pearlite. This showed that the EH36 thick steel plates developed by Jinan Steel meet the welding needs of offshore platforms. The differences of the fusion line shape and heat transfer status between the surface and center of weld joint are main reasons to lead to surface HAZ grain coarser than those of center HAZ, so surface toughness is lower than that of center.%按照EN 10225-2009附录E标准要求，采用50 kJ/cm大热输入埋弧焊工艺焊接厚为100 mm海洋平台用EH36钢板，测试分析了焊态及焊后热处理态焊接接头的组织与性能。结果表明，无论焊态还是焊后热处理态，EH36厚钢板焊接接头的硬度HV10≤280，抗拉强度≥510 MPa，-40℃冲击功均值≥50 J，表面组织以粗大的板条状贝氏体+少量粒状贝氏体为主，心部组织以细小的铁素体+珠光体为主，表明济钢开发的EH36厚钢板满足海洋平台的焊接生产要求。焊接接头表面与心部熔合线形状及传热状态的差异，是导致表面HAZ晶粒比心部粗大、因而表面韧性低于心部的主要原因。