掘进机高强度钢焊接工艺探究

不断提高并强化高强度钢焊接工艺对提高掘进机的实际质量,确保其安全、稳定运行有着至关重要的作用。这不仅是因为高强度钢结构是掘进机的主要结构,更是因为高强度钢结构是掘进机的重要组成部分。所以,科学、合理地进行高强度钢焊接工艺的研究与应用具有十分重要的现实意义。也正因如此,在掘进机的生产环节更应该加强对高强度钢焊接工艺的重视,全面掌握高强度钢焊接工艺的内容,控制好高强度钢焊接工艺的重要参数,从而形成更有利于掘进机生产、加工、制造的高强度钢焊接工艺体系,为有效地提高掘进机的运转性能提供有益的铺垫。本文笔者即结合个人实践工作经验与相关参考文献,就掘进机高强度钢焊接工艺进行粗浅的探索。     

15Mo3和15CrMo异种钢焊接

针对某天然气综合利用项目实施过程中出现的15Mo3与15CrMo的异种钢焊接问题,在相关规范的基础上,制定了焊接工艺、确定了焊接材料,并指导焊接工作对15Mo3和15CrMo钢管道进行了焊接。经检测,所得焊接接头的焊接性能达到了预期效果,且管道运行至今尚未发生泄漏事故,证明了所制定的焊接工艺是正确可行的。     

耐热钢T91与G102的异种钢炉管焊接修复

某发电厂新旧炉管进行更换，材质为T91钢与G102钢异种钢的焊接，我们通过对材料焊接性能分析，依据相关规范，焊接工艺确定采用氩弧焊。通过焊接试验和施工，该工艺焊接接头等各项性能指标全部合格，为同类接头的焊接提供了经验参考。     

低温钢16MnDR大型矩形截面结构焊接工艺及焊接变形

由于大型矩形框架结构纵横向跨度大、截面大等特点,焊接后的焊接变形复杂且难校正。低温钢由于其钢种的特殊性,在焊接工艺和控制焊接变形上加大了难度。只有科学、合理地运用焊接工艺及相关技术措施,才能有效地控制其焊接质量及焊接变形。     

低温钢16MnDR大型矩形截面结构焊接工艺及焊接变形控制浅析

由于大型矩形框架结构纵横向跨度大、截面大等特点,焊接后的焊接变形复杂且难校正。低温钢由于其钢种的特殊性,在焊接工艺和控制焊接变形上加大了难度。只有科学、合理地运用焊接工艺及相关技术措施,才能有效地控制其焊接质量及焊接变形。     

高强度低合金钢的药芯电弧焊

手工电弧焊、埋弧焊,气保护钨极电弧焊和气保护金属极电弧焊工艺已广泛用于焊接高强度钢。近十年药芯焊丝研究的进展促使开发出某些用于焊接标准高强度钢以及较新型的高强度低合金(HLSA)钢的新型药芯焊丝。本文介绍了有关这些新型药芯焊丝的机械性能、焊缝金属扩散红量和所要求的焊接工艺等方面的技术资料。并将利用特定的焊接应用实例从经济角度讨论药芯电弧焊方法的优点。     

钢铝复合板与合金铝管的焊接

本文分析了钢铝复合板与铝镁合金管的焊接工艺难点，介绍了焊接工艺过程。     

Q235钢与1Cr18Ni9Ti不锈钢异种钢焊接接头性能的研究

主要研究Q235钢与1Cr18Ni9Ti不锈钢焊接中存在的焊缝金属化学成分不均匀和熔合区塑性降低(脆性层)这两个问题。采用焊条电弧焊进行焊接,然后对焊接接头进行宏观和微观研究。实验表明,制定合理的焊接工艺,可以在一定程度上控制热影响区晶粒的长大趋势,从而提高Q235和1Ci18Ni9Ti异种钢的焊接性。     

钢-铝激光焊接的关键技术与未来趋势展望

汽车车身多材料结构要求两种不同类型的材料进行连接(如钢-铝、铸铁-铝、铝-镁等).激光焊热量集中,热源能准确控制,应力应变小,与其他焊接方法相比,更适合于钢、铝异种材料的焊接.在分析钢-铝焊接难点的基础上,总结了当前钢-铝激光焊接中常见的焊接缺陷、接头连接形式、表面处理及填加焊料,着重概括了激光焊接工艺参数对焊缝质量的影响,指出钢-铝激光焊接技术未来的发展趋势是设计与开发柔性化夹具,加强钢-铝激光焊接工艺参数优化、焊接缺陷控制、合金元素填料筛选、FeAl脆性金属间化合物与延塑性较好金属间化合物的形成条件、Fe/Al界面结合机理等方面的基础研究,期望为激光焊接多材料车身结构提供重要的技术参考.     

潜艇用高强度高韧性钢的焊接工艺

对于潜艇耐压壳体来说,最重要的问题是在重量最轻的情况下实现最大的承载能力。据此,选用了高强度高韧性钢制作耐压壳体。 在这种情况下,从焊接的角度来说,最重要的就是焊制无裂纹并且有足够的强度和韧性的接头。为确定在防止开裂的条件下屈服强度为80kgf/mm~2的高强度、高韧性钢的焊接工艺及最佳焊接工艺的选择,作者进行了一系列的研究。在此研究的基础上,制造了一个全尺寸模型,并以此作为焊接结构进行了评定。关于焊接裂纹,作者已在文献[1]中作过报道,本文则报道焊接工艺的选择及全尺寸模型制造。     

Interface microstructure evolution of dissimilar friction stir butt welded F82H steel and SUS304

The dissimilar butt welded joint of reduced-activation ferritic/martensitic steel (RAF/M) F82H and austenite stainless steel (AISI304 (SUS304)) were studied by friction stir welding. The effect of the position of the steels and tool plunging was considered in order to prohibit the mixing of the F82H and SUS304. When the dissimilar butt welding was performed such that the F82H plate was on the advancing side and the tool was plunged on the F82H side, defect-free joints could be successfully fabricated. Optical microscopy and EDX analysis were used to characterize the dissimilar joint microstructures and the interface. It was confirmed that the dissimilar joint formed no mixed structure and inter-metallic compounds.     

TP304H与12Cr1 MoV锅炉管异种钢的焊接

利用舍夫勒组织图对韶关发电厂SA2 13TP30 4H与 12Cr1MoV异种钢接头可能出现的焊接组织进行了分析 ,制订出了合理的焊接工艺 ,并对锅炉上的SA2 13TP30 4H与 12Cr1MoV钢焊口进行了施焊 ,经 17个月的运行 ,10 4个焊口未出现爆漏现象     

T92/Super304H异种钢焊接接头的性能研究

根据新型耐热钢T92和Super304H钢的焊接特点制定了适宜的焊接工艺,研究了焊制的T92/Su-per304H异种钢焊接接头的力学性能。结果表明,T92/Super304H异种钢接头的各项力学性均能满足使用要求。焊缝金属的韧性远低于T92钢侧热影响区,焊缝金属的结晶形态对焊缝韧性有很大的影响。焊接接头中焊缝金属的硬度值最高,而T92钢侧热影响区硬度最低,并且不同热影响区部位显微硬度变化较大,Super304H钢侧热影响区硬度变化不大。     

Small-scale resistance spot welding of austenitic stainless steels

Small-scale resistance spot welding (SSRSW) was carried out for austenitic stainless steels. A weld lobe that shows the process window for making sound joints was obtained for type 304 stainless steel thin sheets, and the effects of welding current, force and weld time on joint strength and nugget size were investigated. The cooling rate that was estimated from the solidification cell size was approximately 2.4 × 10⁵ K/s which is almost similar to that produced by laser beam welding. The microstructures of weld zones were almost fully austenitic due to the rapid solidification rate. Despite the fully austenitic microstructure, no hot cracking was found in types 302, 304, 316L, 310S and 347 austenitic stainless steels by SSRSW. Rapid cooling rate in SSRSW made it difficult to predict the microstructures from the conventional Schaeffler diagram.     

Laser power coupling efficiency in conduction and keyhole welding of austenitic stainless steel

Laser welding of thin sheets of AISI 304 stainless steel was carried out with high power CW CO₂ laser. The laser power utilized in the welding process was estimated using the experimental results and the dimensionless parameter model for laser welding; and also the energy balance equation model. Variation of laser welding efficiency with welding speed and mode of welding was studied. Welding efficiency was high for high-speed conduction welding of thin sheets and also in keyhole welding process at high laser powers. Effect of pre-oxidization of the surface and powder as filler material on laser power coupling is also reported. The paper also discusses effect of microstructure on the cracking susceptibility of laser welds.     

304不锈钢局部干法水下激光填丝焊接工艺及焊缝性能研究

目的 采用自主研制的水下激光填丝焊接装备,在304奥氏体不锈钢板材表面进行U形坡口激光填丝焊接试验,为304不锈钢水下修复工作提供技术参考。方法 在功率为5 600 W、焊接速度为6 mm/s、送丝速度为205 cm/min、保护气体流量为15 L/min、排水气体流量为30 L/min的条件下进行焊接试验,并对空气和水下环境下的焊缝进行对比检测分析。通过光学显微镜分析2种环境下焊缝的显微组织;对2种焊缝进行拉伸、弯曲等力学性能测试;采用显微硬度计测试1 kg载荷下不同区域的显微硬度;使用VersaSTAT3F电化学工作站测定在3.5%（质量分数）的NaCl溶液中2种焊缝的开路电位和极化曲线。结果 2种环境下的焊缝均无明显裂纹、气孔等缺陷;显微组织主要由奥氏体和铁素体组成,但2种环境下焊缝的奥氏体晶粒大小和铁素体形状均略有差别,焊缝拉伸断口均为典型的韧性断裂形貌且抗拉强度符合304不锈钢标准。2种环境下焊缝的微观组织和晶粒大小不同,水下焊缝硬度高于空气的。通过分析2种环境下焊缝的开路电位和极化曲线,可知水下焊缝的耐腐蚀性略高。结论 所开发的局部干法水下激光填丝焊接工艺可以满足实际工程中...     

304不锈钢与PA66塑料激光焊接工艺研究

目的 研究304不锈钢和PA66(尼龙)的焊接工艺,提高焊缝剪切强度。方法 采用500 W光纤激光器对异种材料进行搭接焊接实验,对激光功率、焊接速度、离焦量、焊接次数进行四因素四水平正交实验,并且测试焊缝剪切强度。结果 当激光功率为350 W,焊接速度为600 mm/s,离焦量为1 mm,焊接次数为3时,焊缝剪切强度达到最大的58 MPa。极差分析结果表明,影响焊缝剪切强度的因素依次为激光功率、离焦量、焊接速度、焊接次数。结论 微观结构分析结果表明,焊缝在PA66塑料侧呈现韧性断裂;在304不锈钢侧呈现韧性脱落,塑料和不锈钢有紧密的贴合,这种结构有利于提高焊缝的剪切强度。     

Predicting recrystallized grain size in friction stir processed 304L stainless steel

A major dilemma faced in the nuclear industry is repair of stainless steel reactor components that have been exposed to neutron irradiation. When conventional fusion welding is used for repair, intergranular cracks develop in the heat-affected zone(HAZ). Friction stir processing(FSP), which operates at much lower peak temperatures than fusion welding, was studied as a crack repair method for irradiated 304 L stainless steel. A numerical simulation of the FSP process in 304 L was developed to predict temperatures and recrystallized grain size in the stir zone. The model employed an Eulerian finite element approach,where flow stresses for a large range of strain rates and temperatures inherent in FSP were used as input. Temperature predictions in three locations near the stir zone were accurate to within 4%, while prediction of welding power was accurate to within 5% of experimental measurements. The predicted recrystallized grain sizes ranged from 7.6 to 10.6 μm, while the experimentally measured grains sizes in the same locations ranged from 6.0 to 7.6 μm. The maximum error in predicted recrystallized grain size was about 39%, but the associated stir zone hardness from the predicted grain sizes was only different from the experiment by about 10%.     

Formation and evolution of layered structure in dissimilar welded joints between ferritic-martensitic steel and 316L stainless steel with fillers

Dissimilar high-energy beam (HEB) welding is necessary in many industrial applications. Different composition of heat-affected zone (HAZ) and weld metal (WM) lead to variation in mechanical properties within the dissimilar joint, which determines the performance of the welded structure. In the present study, appropriate filler material was used during electron beam welding (EBW) to obtain a reliable dissimilar joint between reduced-activation ferritic-martensitic (RAFM) steel and 316 L austenitic stainless steel. It was observed that the layered structure occurred in the weld metal with 310S filler (310S-WM), which had the inferior resistance to thermal disturbance, leading to severe hardening of 310S-WM after one-step tempering treatment. To further ameliorate the joint inhomogeneity, two-step heat treatment processes were imposed to the joints and optimized. δ-ferrite in the layered structure transformed into γ-phase in the first-step normalizing and remained stable during cooling. In the second-step of tempering, tempered martensite was obtained in the HAZ of the RAFM steel, while the microstructure of 310S-WM was not affected. Thus, the optimized properties for HAZ and 310S-WM in dissimilar welded joint was both obtained by a two-step heat treatment. The creep failure position of two dissimilar joints both occurred in CLAM-BM.     

储能缝焊工艺对304不锈钢接头性能的影响

为研究电容储能缝焊工艺对304不锈钢接头性能的影响规律,对0.5 mm厚304不锈钢板进行了缝焊工艺实验,通过接头拉剪力检测和金相显微组织观察,对比了不同焊接速度、充电电容和放电频率下的缝焊接头组织特点,并分析了各工艺参数对接头拉剪力、熔核宽度、焊缝重叠量和焊透率的影响.结果表明:储能焊焊缝中心晶粒细小,熔合区为柱状晶,重叠部位晶粒粗大,接头组织呈现不均匀性,随着充电电容的增大晶粒变得更细密,组织不均匀程度显著降低,焊接速度和放电频率增大导致晶粒组织粗化并出现缩孔缺陷,提高电极压力可克服缩孔并使组织趋向均匀;充电电容对接头拉剪力的影响较小,焊接速度、充电电压、放电频率和电极压力调到一个合适值后,继续增大参数值对接头拉剪力影响很小;焊接速度的增大引起焊缝熔核宽度和重叠量急剧下降,充电电压增大引起焊缝焊透率下降过多,导致飞溅、过烧、毛刺等焊接缺陷的产生.因此,304不锈钢储能缝焊应采用低的焊接速度、较小的充电电压和较高的电极压力。