共查询到19条相似文献,搜索用时 296 毫秒
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X80高强度高韧性厚壁管线钢及高速埋弧焊接头性能 总被引:3,自引:0,他引:3
研究分析了西气东输二线用X80管线钢的组织和性能,通过TEM观察了晶体结构特征,表明X80管线钢晶粒细小、晶界纯净,金相组织均匀,力学性能稳定,是一种高强度、高韧性管线钢.针对这种X80管线钢高速埋弧焊,通过焊丝焊剂的成分设计和焊缝组织设计,以及高纯净度炼钢技术,研制出高性能焊丝焊剂,采用优化的焊接工艺,使焊接接头不但具有较好的力学性能,而且焊接工艺性能良好,实现了高强度厚壁管线钢的高速焊接,焊速可达1.70 m/min左右. 相似文献
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针对海洋石油工业的发展趋势,以海洋用高钢级X80管线钢为研究对象,采用焊接工艺试验、力学性能测试及显微分析技术,研究了焊条电弧焊工艺下X80管线钢焊接接头的性能和热影响区的组织变化规律.结果表明:采用设计的焊条电弧焊工艺参数对海洋用X80管线钢进行焊接,可以得到合格的焊接接头.X80管线钢母材和焊接接头所具有的针状铁素... 相似文献
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高钢级油气输送管道环焊缝双丝焊接技术的应用 总被引:2,自引:0,他引:2
简介了输送管线的传统焊接工艺,以X80和X100级管线钢熔化极气体保护焊(GMAW)为例,讨论了高钢级管线钢焊接时存在的主要问题,并对比分析了X80级管线钢单丝焊和双丝焊的接头力学性能差别。侧重介绍了双丝焊工作原理及其优点,以及双丝焊接技术在某海底管线敷设中的应用情况。结果表明,高钢级管线钢环焊缝现场焊接时采用双丝焊接技术,不仅可以提高焊缝质量和焊接效率,而且可以降低焊接热影响区组织粗化和软化程度,有利于焊接接头力学性能的改善。 相似文献
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基于成分匹配与组织匹配设计原则,确定了X100管线钢焊缝金属的合金系.结合焊缝金属的合金化原理,定量计算出需要向焊缝中过渡的合金元素种类及其含量,设计并制成X100管线钢匹配用自保护药芯焊丝.选用合适的焊接工艺参数进行试焊,并对焊接接头的性能进行分析.结果表明,所研制的药芯焊丝焊接接头的力学性能优异,抗拉强度达到795 MPa,屈服强度达到615 MPa,冲击吸收功达到47.7 J(-40℃);焊缝组织主要为板条状贝氏体和粒状贝氏体,另有少量针状铁素体穿插其中,能够与母材实现较好的组织匹配. 相似文献
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通过分析高强度低合金钢焊缝熔敷金属常见显微组织对其力学性能的影响,确定X80管线钢用埋弧焊丝熔敷金属组织应以大量针状铁素体(AF)和少量粒状贝氏体(GB)的复合组织.从相变动力学原理出发,结合针状铁素体(AF)非自发形核机制和微合金组织韧化理论,选择Mn-Ni-Mo-Ti-B合金系进行X80管线钢匹配焊丝的试制.结果表明,合理选择和控制合金元素,可以获得理想的焊缝熔敷金属组织和强韧性以及低温韧性要求,试制的1号焊丝能够满足X80管线钢的使用要求. 相似文献
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利用双熔敷极焊条电弧焊技术对X80管线钢进行了焊接,并在焊接接头成分、组织及耐蚀性方面与传统焊条电弧焊进行了对比分析.结果表明,双熔敷极焊条电弧焊技术熔敷效率高,但受其结构及药皮重量系数的影响焊缝中合金元素的含量比普通焊接焊缝的低,且焊缝中多边形铁素体含量较高,另一方面由于对母材的热输入较低,使得其粗晶区组织较为细小,这有利于其性能的提高;对0.5 M Na2CO3-1 M NaHCO3溶液及通饱和CO2的NACE A溶液中的耐蚀性研究发现,焊缝及粗晶区耐蚀性均差于母材,且采用双熔敷极焊条电弧焊技术有利于提高焊缝及粗晶区的耐蚀性. 相似文献
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摘要: 采用等离子弧焊对3 mm厚的Q345低合金钢与430不锈钢进行异种钢焊接,并对接头微观组织、力学性能及耐腐蚀性能进行了研究。结果表明,当转弧电流为100 A时,等离子弧焊Q345B/430异种钢接头的焊缝组织为均匀分布的马氏体及针状铁素体,焊接接头综合性能优良。随着电流的增大,焊缝组织转变为粗大板条马氏体及铁素体。两侧热影响区组织均发生一定程度的粗化,且Q345B侧热影响区出现魏氏组织。焊接接头于焊缝处显微硬度最大,不同转弧电流条件下异种钢显微硬度分布趋势大致相同。不同转弧电流下,焊接接头抗拉强度均与430不锈钢相近,且均断裂在靠近焊缝的430母材侧,转弧电流为100 A时接头抗拉强度最大值427 MPa。焊接接头的耐腐蚀性能与焊接电流呈负相关趋势。
创新点: 试验结果为铁素体低合金钢与铁素体不锈钢异种钢接头的应用提供了工艺数据与支撑。 相似文献
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0IntroductionWith the rapid development of oil and gas industry,the pipeline construction is in the ascendant in China.Forconsideration of cost and safety,the strength of pipelinesteel and the working pressure of pipeline have been great-ly increased.In the previous pipeline projects X65steelwas used and now West-to-East Transportation Project forexample is mainly using X70steel,and X80steel hasdrawn great attention and is expected to be employed insome trial pipelines in the future.Steel … 相似文献
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开发了一种新型全位置立向下焊条,采用有约束的配方均匀设计,对焊条配方进行了优化,采用GX-Ⅲ高温物性测试仪对焊条药皮的熔化特性进行了研究.结果表明,开发的全位置立向下焊条具有优良的工艺性能,焊缝成形美观,易脱渣,电弧稳定,飞溅率小等;该焊条具有较高的抗拉强度、屈服强度和较高的低温冲击韧性,能广泛应用于重要结构焊接.通过对焊接接头断口、金相组织以及焊缝成分和焊接接头横截面硬度分析表明了焊缝具有较高力学性能.形成了一整套开发全位置立向下焊条的新方法,该方法具有开发周期短、成本低、质量高的特点. 相似文献
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采用E9018-G焊条手工电弧根焊,用低组配药芯焊丝自保护焊和高组配焊条手工电弧焊填充盖面工艺焊接了X80钢级大变形钢管环焊缝,对环焊缝接头进行力学性能测试和金相观察分析。结果表明,两种焊接工艺评定结果符合API Std.1104标准要求。采用低组配药芯自保护焊焊接的焊缝冲击功和裂纹尖端张开位移值比采用高组配焊条手工电弧焊焊接的高。前者的焊缝组织为PF(多边化铁素体)+P(珠光体),后者的焊缝组织为 PF+IAF(针状铁索体)+P。二者熔合区的组织均为粒状贝氏体,粗晶区和细晶区没有淬硬马氏体组织出现,保证了热影响区具有很好的断裂韧性。 相似文献
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To increase transport efficiency and to lower the costs of pipeline construction, longitudinally submerged arc welded (LSAW) pipes with larger diameters and thicker walls have been increasingly used by the pipeline industry. For example, in Russia, the LSAW pipeline in the Bovanenkovo-Ukhta project was recently constructed with K65 steel (the highest grade of the Russian natural gas pipeline), which is similar in specifications and yield strength requirement (550 MPa grade) to API X80 but has a stricter low temperature toughness value of 60 J at -40 degrees C (compared to - 20 degrees C for API X80 grade) due to the extreme Arctic environment. Although weld metal with acicular ferrite (AF) has been developed to meet the requirement of low temperature toughness, the main objective of the present work was to clarify the microstructural evolution and the resulting changes in mechanical properties after the bending process. Hot bending pipes are necessary links in the construction of pipeline lying, which make more stringent standards for the strength and low temperature toughness. That puts forward a challenge especially to the weld bead because of the deterioration of toughness during the hot bending process. In this work, submerged arc welding wire with high strength and toughness was developed for K65 hot bending pipes, and the alloying elements of Mn, Ni, Mo were considered to estimate the microstructure evolution and the effect of low temperature toughness for the weld metal. The results showed the low temperature toughness at -40 degrees C reached 90 similar to 185 J and 65 similar to 124 J for weld metal of straight seam pipe and hot bending pipe respectively, which reflect the excellent role of alloying elements of Mn, Ni, Mo. Microstructure characterization revealed that the weld metal, which originally consisted mainly of AF in the as-deposited condition, became predominantly composed of bainitic ferrite (BF) after hot bending. In addition, the large size cementite along the grain boundary was also the reason for the deterioration of toughness. It is found that reaustenisation caused a small austenite grain-sized matrix, which brought about a very high volume fraction of bainite. However, the low temperature toughness for hot bending pipe was improved to 124 J for the weld metal with 0.2% Mo, in which about 67.1% of high angle grain boundary were found. It is clear that the process of reaustenitisation during the bending process plays an important role in successful microstructural design for the steel weld metals. 相似文献
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焊缝金属的强韧化是超级钢焊接中的一个技术难题,要实现焊缝的强韧化,并避免冷裂纹,需开发与母材性能相匹配的焊接材料.对400 MPa级超级钢主要通过合金化控制焊缝组织使其获得针状铁素体即可获得理想的强韧性.通过大量工艺试验研究,结合400 MPa级超级钢的组织性能特点,研制开发了一种400 MPa级超级钢专用焊条.检测结果表明,该种焊条形成的焊缝金属组织为细小针状铁素体,焊缝金属屈服强度为435 MPa,抗拉强度为612 MPa,冲击吸收功为148 J,其组织和性能同400 MPa级超级钢能很好的相匹配,达到了预期目的. 相似文献