【摘要】 系统研究了世界首台630℃超超临界火电机组高温管道用新型马氏体耐热钢G115(08Cr9W3Co3VNbCuBN)的焊接性、配套焊接材料开发及焊接工艺。研究表明，G115钢焊接存在显著热裂纹倾向，一定冷裂纹倾向（预热≥150℃可有效抑制）及时效脆化倾向（长期高温服役冲击韧性下降）；同时，其含B成分设计可能降低热影响区Ⅳ型蠕变开裂风险。国内自主研发的G115专用焊条、埋弧焊材及氩弧焊丝熔敷金属高温持久强度优异，外推10万小时强度可达母材80%以上，力学性能匹配良好。对比焊条电弧焊（SMAW）、埋弧焊（SAW）、振动送丝氩弧焊（TIPTIG）、全自动氩弧焊（AUTOTIG）四种工艺发现：TIPTIG与AUTOTIG接头的热影响区宽度显著减小（1.7～2.5 mm），冲击吸收能量达100 J以上；SMAW与SAW接头冲击韧性为41～50 J，均满足技术要求（≥41 J）；窄间隙氩弧焊工艺因窄化高温薄弱区，更利于提升接头持久寿命。基于上述成果，研究团队牵头编制了CSTM团体标准，规范了焊接材料验收、接头性能指标、工艺参数及质量检验方法，为G115钢在电力工程的应用提供了技术支撑。更多还原

【Abstract】 A systematic study was conducted on the weldability, development of matching welding materials, and welding processes for the new-generation martensitic heat-resistant steel G115(08Cr9W3Co3VNbCuBN), used in high-temperature pipelines of the world’s first 630 ℃ ultra-supercritical thermal power unit. The research indicates that G115 steel welding exhibits a significant tendency toward hot cracking, a certain susceptibility to cold cracking(effectively mitigated by preheating ≥150 ℃), and a propensity for aging embrittlement(manifested as reduced impact toughness during long-term hightemperature service). Concurrently, its boron(B)-containing composition design potentially lowers the risk of Type IV creep cracking in the heat-affected zone(HAZ). Domestically developed dedicated welding materials for G115, including electrodes, submerged arc welding consumables, and argon arc welding wires, demonstrate excellent high-temperature rupture strength in their deposited metal. Extrapolation of data from tests exceeding 10,000 hours indicates that the 100,000-hour rupture strength can reach over 80% of the base metal, with satisfactory matching of mechanical properties. Comparative analysis of four welding processes—shielded metal arc welding(SMAW), submerged arc welding(SAW), vibrating wire feeding argon arc welding(TIPTIG), and automatic argon arc welding(AUTOTIG)—revealed that: TIPTIG and AUTOTIG joints exhibit significantly reduced HAZ widths(1.7-2.5 mm) and achieve impact absorbed energy exceeding 100 J; SMAW and SAW joints exhibit impact toughness ranging from 41-50 J, all meeting the technical requirement(≥41 J); Narrow-gap argon arc welding processes enhance the joint’s long-term creep life by narrowing the high-temperature weak zone(HAZ).Based on these findings, the research team spearheaded the development of CSTM group standards. These standards have standardized welding material acceptance criteria, joint performance indicators, key process parameters(e.g., preheating temperature 200-300 ℃, interpass temperature 150-300 ℃, post-weld heat treatment at 770±10 ℃), and quality inspection methods, providing crucial technical support for the engineering application of G115 steel in power generation projects.更多还原