大口径油气管道环焊技术的进展及在宝钢的应用

介绍了当前管道工业的发展及管道焊接技术的进展情况,并阐明了管道全位置下向焊接技术的特性.管道环焊缝是由根焊、热焊、填充焊、盖面焊等不同焊道组成.对常用的手工焊、半自动焊和自动焊接方法在管道环焊缝不同焊道焊接时的应用以及各自特点做了介绍,还对焊接材料的选用、焊接设备的选型作了描述.宝钢铜管厂大口径直缝埋弧焊管(UOE)项目即将投产,投产后大口径焊管产品使用技术的研究势在必行,宝钢应尽快开展大口径UOE焊管的环缝焊接技术的研究,为将来的推广应用提供必要的技术支撑.     

海洋管线铺设环焊技术现状及宝钢研究进展

综述了当前深水海洋管线钢管铺设方法以及对应的施工环缝焊接技术,海管高效自动环缝焊接技术成为今后的发展趋势.介绍了双车双炬熔化极气体保护自动焊接技术、闪光对焊技术、激光—电弧复合焊接技术、非真空电子束焊接技术等在海管施工焊接领域具有很大应用潜力的技术.当前,宝钢UOE钢管产品致力于高等级海管的生产与经营,在UOE海管自动环缝焊接方面开展了研究,旨在为用户提供相应技术服务与支撑.     

3 200 m3高炉本体钢结构安装施工技术

高炉本体的焊接是高炉结构安装的最关键的环节,介绍了高炉炉壳安装施工的过程.施工中立缝采用气电立焊接,环缝采用埋弧自动焊接等新技术、新工艺,经过实际焊接比较,立缝焊接比手工焊接提高功效30倍,环缝焊接比手工焊接提高功效7倍.     

特殊条件下管线钢管自动环缝焊接性研究

根据海外管线钢管用户需求,针对典型规格X70M大口径UOE管线钢管,在不超过0.25 kJ/mm超低热输入以及焊丝高强匹配条件下进行熔化极气体保护自动环缝焊接。通过研究实际焊接过程中环焊接头冷裂纹敏感性、焊后环焊接头强化、硬化与脆化倾向,全面评价X70M管线钢管在这种具有加速失效特征的特殊焊接条件下的环缝焊接性。同时,将特殊条件下X70M管线钢管接头使用性能特征与现场施工正常主流焊接工艺条件下的接头性能指标进行比较,从而证实了X70M管线钢管良好的环缝焊接性,并指出了特殊条件下管线钢管自动环缝焊接性评价结果对现场施工焊接的重要指导意义。结果表明,即使在特殊苛刻焊接条件下,X70M管线钢管焊接性仍能满足现场施工焊接要求。     

PLC在汽车车桥环缝自动焊接设备中的应用

针对目前可靠的焊接质量、高自动化程度的车桥焊接设备的研究制造成为当今车桥焊接领域的发展趋势,本文研制了一种基于PLC自动控制技术的汽车车桥环缝自动焊接设备,设计出PLC控制焊接过程的控制程序,使车桥环缝焊接生产线实现实时自动控制.极大地提高了车桥环缝焊接生产线工作的稳定性、可靠性、适应性、经济性以及抵抗各种干扰的能力,具有较高的市场应用前景.     

高炉自动焊机技术的应用

文章介绍了在新疆八一钢厂2 500 m3新1#高炉工程中采用GHH-Ⅱ型高炉横缝埋弧自动焊机焊接炉壳横环缝,采用GLH-Ⅱ型气电立焊机焊接炉壳立缝及锥体立缝,进行焊接工艺评定及确定有关焊接工艺参数的技术,为今后类似工程施工提供了经验和借鉴。     

3 200 m3高炉炉壳立缝、环缝自动焊接技术

介绍了天钢3 200 m3高炉炉壳自动焊技术和工艺,该工程对焊接设备进行了改造,改变了传统高炉壳体焊接工艺,并在国内首次在高炉壳体结构焊接工作中全面使用立缝、环缝自动焊,保证了工期的按时完成,取得良好的经济与社会效益.     

氧化铝种分槽体横环缝自动化焊接的分析

通过对大型氧化铝种分槽主体建设施工现场的研究,分析了氧化铝种分槽体自动化焊接施工的特性,开发研制成功了罐体立缝高效气电立焊机和横环缝埋弧自动焊接操作机。通过几年来在三十几座氧化铝种分槽主体施工工程中的应用,其焊接技术先进,焊接效率高,焊接质量好,极大地减轻了工人的劳动强度,降低了综合成本,有广阔的前景。     

管线钢管纤维素焊条高速环焊接头韧性分析

针对宝钢X65级UOE管线钢管,应用纤维素焊条进行高速环缝打底焊接和热焊,填充盖面焊接选用低氢焊条,并对环焊接头进行冲击韧性和CTOD断裂韧性分析。同时,将纤维素焊条高速环焊接头与全部低氢焊条环焊接头在冲击韧性和断裂韧性方面进行比较,结果表明,无论是焊态还是消氢处理态,针对X65这种较低强度钢管,纤维素焊条高速环焊接头均具有良好的冲击韧性和断裂韧性。纤维素焊条高速环缝焊接在高强度管线钢管中的应用有待于进一步研究。     

管线钢WIC试验对UOE钢管现场施工环焊的指导

WIC试验是加拿大焊接协会20世纪80年代开发的一种用于评价管线钢材料抵抗焊接氢致裂纹能力的试验方法,其反映了管线钢材料的可焊性,尤其是制管后管线钢管现场施工环缝焊接性。因此可根据WIC试验的结果,制定UOE钢管现场施工环焊坡口设计与组对、环缝根焊方法选择与工艺制定、环焊后续处理等方面的指导原则,为相关用户提供技术支撑。     

Evaluation of automatic girth weldability of pipeline in special conditions

To meet the requirements of pipeline consumers abroad, in this study, an automatic gas metal arc welding type of girth welding was performed with a heat input of no more than 0.25 kJ/mm and high-strength solid-wire matching for an X70 M large-diameter UOE pipeline.An integral evaluation of the X70 M pipeline girth weldability was performed with respect to the girth-weld cold-cracking sensitivity during the welding process and the strengthening, hardening, and embrittlement of the girth weld joint after girth welding in especially rigorous welding conditions with accelerated failure characteristics.The performance of the above girth weld joint with joints welded using the main construction-field girth welding procedure was compared to ensure the good girth weldability of the X70 M pipeline.The results of this study have important supervisory significance for field-construction girth welding.Finally, the girth weldability of the X70 M pipeline was found to satisfy the field construction requirements even when the welding conditions are especially rigorous.     

Field girth weldability evaluation of X70 UOE pipeline

Based on API STD 1104-2005 and CSA Z662-2007,field girth welding tests and girth weldability evaluations were executed for three types of wall thickness X70 UOE pipeline,in which the most popular main line girth welding method,single-wire automatic gas metal arc welding(GMAW),was used. The welding procedure specification was optimized to achieve a good quality and cold-crack-free girth weld joint without preheating or post-weld heat treatment. In addition,porosities,inclusions,and incomplete fusion defects were avoided. The tensile strength,bending,Vickers hardness,Charpy V-notch impact toughness,and crack tip opening displacement fracture toughness of the girth weld joint were evaluated,and the joint exhibited good mechanical performance. Thus,the field girth weldability of Baosteel's X70 UOE pipeline is excellent for automatic GMAW.     

Automatic girth welding and performance evaluation of the joints of hot-induction-bend and line pipes with different wall thickness

During the process of laying long-distance oil and gas transmission pipelines,the hot-induction-bend method is extensively used when the direction has to be changed.By considering the pipeline's ongoing processing and loading states during service,the pipeline that is generally used exhibits thicker walls than those that are observed in the line pipe.As such,during pipeline construction,hot-induction-bend and line pipes with different wall thickness are girth-welded.The chemical composition of hot-induction-bend and line pipes differs,with the carbon content being particularly higher in the hot-induction-bend pipe;it also depicts a higher carbon equivalent,which makes it possible to modify the girth of the pipe.In this study,using Baosteel's standard X70M UOE hotinduction-bend and line pipes,solid-wire automatic gas-metal-arc girth welding was performed and the performance of the girth-welded joint was evaluated.Furthermore,the weldability of the pipeline girth and the microstructure of the girth-welded joint were analyzed.The results reveal that Baosteel's standard UOE hot-induction-bend and line pipes exhibit good girth weldability,and their technical quality can be guaranteed in case of consumer fieldconstruction applications.     

Investigation of the impact toughness of self-shielded flux-cored wire girth welds for X80 pipelines

Self-shielded flux-cored wire is a convenient and efficient consumable for pipeline field girth welding because of its self-protection characteristic and high deposition rate,especially for remote construction sites in rugged terrain. From the perspective of pipeline safety,the impact toughness of the girth welds is an important factor in pipeline integrity,which determines the crack arrest behavior in the girth welds. Therefore,improving the girth weld impact toughness is of primary importance in the field of pipeline girth welding. Three self-shielded flux-cored wires comprising different chemical composition systems have been applied to large diameter X80 UOE( U-ing-O-ingExpanding) pipeline semi-automatic girth welding,and the impact toughness of the welds has been evaluated by girth weld chemical composition analysis and microstructural analysis using scanning electron microscopy( SEM) and energy dispersive spectrometry( EDS) to investigate pipeline girth weld impact toughness and find ways to improve it.This helps in determining the main factors that influence girth weld impact toughness. Pipeline girth weld impact toughness is mainly determined by the final microstructure produced in the solid-state phase transition. In the as-weld state,acicular ferrite( AF) and fine bainite( FB) are a benefit to the impact toughness. For multilayer semiautomatic self-shielded flux-cored wire welding,the normalizing and tempering function of the latter beads to the initial beads plays an important role in the transition of girth weld microstructure,which affects the impact toughness. The original AF and FB and the corresponding heat treatment microstructure of the fine and uniform block ferrite and pearlite result in very good impact toughness. The following two mechanisms are found to promote the production of AF and FB in the girth weld. First,elements promoting the broadening of the austenitic region,such as Ni,C,Cu,and Mn,induce low temperature phase transitions and restrain the opposing function of Al,which is a benefit to the production of AF and FB. Second,dispersed high-melting-point inclusions,especially Al2O3,induce the nucleated production of AF. The advantageous function of inclusions is determined by their shape,distribution,and dimension. Dispersed spherical inclusions of small dimension are a benefit to the production of AF,and result in good impact toughness.     

Research status of corrosion environment failure and safety assessment of pipeline welded joint

Pipeline transportation is an economical,safe,and efficient transportation method for transporting oil,natural gas,mineral slurry,and other fluids.Welding is the most critical construction process in pipeline engineering and is crucial in the safe operation and service of an entire pipeline system.Theoretically,the girth welded joint is the weakest link in a pipeline system.The unevenness of the structure and performance of the joint caused by welding frequently results in the failure of the welded joint before the failure of the base material of the pipe body,causing the pipeline to leak or even break.For steel pipes used in an acidic corrosive medium environment,the integration of the corrosive medium and mechanical load will accelerate the failure of the welded joint.This article reviews the failure modes of pipeline welded joints in acidic corrosive media,including stress corrosion cracking,hydrogen-induced cracking,and corrosion fracture,and corrosion fatigue considering the diffusion and accumulation of H+at the crack tip.It also reviews service pipelines in acidic corrosive media.The general processing technology of pipe joint engineering critical assessment(ECA)is investigated to provide a reference for the future development of technology in this field.     

Girth weldability and welding process of Baosteel X80 UOE linepipes

An analysis of the girth weldability of Baosteel X80 UOE (U-ing-O-ing-Expanding) linepipes was conducted using manual shielded metal arc welding (SMAW) and semiautomatic self-shielded flux cored wire arc welding (FCAW).A technical specification for the optimum quality of a girth welding joint was obtained through a large amount of testing.According to the requirements of America Petroleum Institute(API) standard 1104 and the standards of the 2nd West-East natural gas transmission pipeline project,the mechanical properties of a girth welding joint were estimated.In addition,the effect of the girth welding procedure specifications and the consumable’s suitability on the impact toughness of the girth welding joint was discussed.