超级双相不锈钢的焊接性及焊接技术研究

本文对双相不锈钢的焊接性进行了分析,介绍了焊接过程中的关键技术点,本文通过对奥氏体-铁素体双相不锈钢材料的介绍、焊接性能和经验总结,得出一种较为成熟的可以获得优质焊接接头的焊接工艺方法。     

铁素体-奥氏体型双相钢CD4MCu的熔炼研究

铁素体-奥氏体型双相不锈钢得益于其独特的双相组织结构,将奥氏体不锈钢的优良塑韧性与铁素体不锈钢的高屈服强度有机地结合起来。此外,材料的高屈服强度及双相相界的机械屏障作用,使双相钢材料的抗应力腐蚀性能大大优于普通奥氏体不锈钢。由于双相不锈钢具有奥氏体不锈钢和铁素体不锈钢的优点,     

不锈钢船用焊接技术及焊接材料

介绍了我国造船业的发展及对焊接材料的需求，重点讨论了液化天然气（LGN）船及双相不锈钢化学品毒的焊接技术。对于液化天然气设施，焊逢金属中铁素体含量是影响-196℃超低温韧性的主要因素，可以通过调整Creq、Nieq来控制焊缝中的铁素体含量。对于双相不锈钢化学品船焊缝和焊接HAZ，只有保证足够的奥氏体数量（铁素体在5％-40％），才能得到满意的力学性能与耐腐蚀性能。     

不锈钢焊接冶金的研究进展

介绍了奥氏体不锈钢焊缝中铁素体含量、母材和焊缝中合金元素对焊接接头性能的影响，同时还介绍了双相不锈钢、铁素体不锈钢、马氏体不锈钢焊接冶金的研究进展，并指出了研究不锈钢焊接冶金的重要意义。     

2205双相不锈钢管焊接工艺评定

铁素体-奥氏体双相不锈钢,简称即双相不锈钢(DSS),具有优良的力学性能和耐蚀性能,2205(也称22Cr)双相不锈钢管材在石油及天然气工业、海洋工程、化学工业等行业具有广泛的用途。该材料焊接有许多技术特点,工艺参数对接头的组织和性能有很大影响。对D508×15.9mm规格钢管制管纵缝和现场环焊缝焊接工艺评定进行介绍。     

热输入对双相钢药芯焊丝电弧焊接头组织和性能的影响

对2205双相不锈钢板进行了药芯焊丝电弧焊,研究了不同热输入(8.32,11.02,14.04,17.39kJ·cm~(-1))对焊接接头显微组织、铁素体含量、冲击性能、显微硬度和耐点腐蚀性能的影响。结果表明:2205双相不锈钢接头焊缝、熔合区及热影响区均由奥氏体和铁素体组成,铁素体含量随着热输入的增加而逐渐降低;焊接热输入在14.04kJ·cm~(-1)时,接头区域铁素体体积分数基本满足40%～60%的要求;随着焊接热输入的增加,接头焊缝和热影响区的硬度略有降低,焊缝金属的冲击吸收功先升高后下降,热影响区的点腐蚀速率变化不大,焊缝的点腐蚀速率则先下降后升高;焊接热输入在14.04kJ·cm~(-1)时,2205双相不锈钢焊接接头的耐点腐蚀性能最好。     

2205双相不锈钢焊接接头裂纹失效机理分析

根据金相分析和断口扫描电镜分析，对2205双相不锈钢焊接接头裂纹进行了分析。结果显示热影响区上裂纹为应力腐蚀开裂。由于焊接的热作用导致焊缝热影响区沿铁素体晶界析出的二次奥氏体和铁素体／奥氏体比例失调，从而造成应力腐蚀开裂。     

ZG0Cr25Ni7Mo2N低碳双相不锈钢补焊工艺的研究

针对ZG0Cr25Ni7Mo2N低碳双相不锈钢产品在生产中出现的焊接不稳定问题,经常出现返修补焊的现象,论文对ZG0Cr25Ni7Mo2N低碳双相不锈钢铸件补焊进行研究,使用焊条电弧焊的方法,选用2209-15低氢焊条,采用多层多道焊,通过确定合理的工艺参数及焊接方法,分析焊接接头的金相组织,对焊接接头力学性能进行检测,验证ZG0Cr25Ni7Mo2N低碳双相不锈钢在使用2209-15低氢焊条,采用所选焊接工艺条件下,焊接接头是否能满足产品要求。解决双相不锈钢铸件焊接产品在精加工出现缺陷。经过试验确定,焊接热影响区主要由双相组织组成,焊缝区域主要由奥氏体组织和少量铁素体组织组成,焊接接头力学性能满足使用要求.     

海洋工程用双相与超级双榧不锈钢焊条的研制

研制了双相和超级双相不锈钢焊条,通过准确的焊缝合金、焊芯成分及药皮组分的设计,研制出的焊条具有良好的焊接工艺性能,焊缝组织具有比例恰当的铁素体和奥氏体含量,两类焊条焊缝,尤其是超级双相不锈钢焊条焊缝,均具有极佳的耐点腐蚀性能、耐晶间腐蚀性能和良好的力学性能。     

铁素体/奥氏体双相不锈钢高能量密度焊接研究现状

铁素体/奥氏体双相不锈钢独特的组织特征使其兼具塑韧性好、耐腐蚀性能好、强度高的优势，在海洋工程、石油化工等多个领域具有广阔的应用前景。高能量密度焊接技术具有热影响区窄、变形程度小、残余应力低、焊接速度快、生产效率高等显著优点，近年来引起了学者的高度关注。从焊接方法和焊接工艺2个方面介绍了双相不锈钢高能量密度焊接技术的研究进展，综述了高能量密度焊接和焊后热处理态接头的组织和性能，最后提出目前双相不锈钢高能量密度焊接研究中存在的问题并给出了未来的研究方向。     

反应堆压力容器不锈钢焊接中铁素体的控制

对不锈钢焊缝的凝固模式以及铁素体对焊缝质量的影响进行分析,结果表明不锈钢焊缝中的铁素体含量决定了焊缝的凝固模式。当铁素体数FN在5~20之间时,可以防止凝固裂纹沿晶粒边界的扩展。由此提出控制不锈钢焊材化学成分的方法,可避免或减少不锈钢凝固裂纹的产生。经过对多种铁素体测量方法的综合分析,建议采用化学计算和磁性测定相结合的方法进行测定。     

Modeling and analysis of ferrite number of stainless steel gas tungsten arc welded plates using response surface methodology

The prediction of delta ferrite content expressed in terms of ferrite number in austenitic stainless steel welds is very helpful in assessing its performance. The final ferrite content determines the properties of weldments such as strength, toughness, corrosion resistance, and phase stability. This paper presents a study on the effect of process parameters on ferrite number in 202 grade stainless steel gas tungsten arc welded plates (GTAW). Experiments were conducted based on response surface methodology. The ferrite number was determined by using a ferrite scope and by using DeLong diagram. A mathematical model was developed correlating the important controllable GTAW process parameters like welding gun angle, welding speed, plate length, welding current, and shielding gas flow rate with ferrite number. The adequacy of the model was checked using analysis of variance technique. The developed model is very useful to quantitatively determine the ferrite number. The main and interaction effects of the process parameters are presented in graphical form that helps in selecting quickly the process parameters to achieve the desired results.     

Microstructure and mechanical properties of similar and dissimilar stainless steel electron beam and friction welds

Microstructure and mechanical properties of similar and dissimilar welds of austenitic stainless steel (AISI 304), ferritic stainless steel (AISI 430), and duplex stainless steel (AISI 2205) have been studied. Welding processes electron beam welding and friction welding were used. Optical, scanning electron microscopy, and electron probe microscopy were carried out to study the microstructural changes. Residual stress, hardness, tensile strength, and impact toughness testing were conducted to study mechanical behavior. Dissimilar metal electron beam welds of austenitic–ferritic, ferritic–duplex, and austenitic–duplex stainless steel welds contained coarse grains, which are predominantly equiaxed on austenitic, duplex stainless steel side, and they are columnar on the ferritic stainless steel side. Diffusion of elements was significant in electron beam welding and insignificant in friction welds. Austenitic–ferritic stainless steel exhibited tensile residual stress on the ferritic stainless steel side adjacent to the interface, compressive stresses on the austenitic stainless steel side that matches with the delta ferrite microstructure observed in this region. High compressive stresses were noted on duplex stainless steel side interface compared to austenitic stainless side interface. The highest tensile strength was observed in duplex–austenitic stainless steel joints. The impact strength and notch tensile strength of electron beam weldments are higher than the friction weldments. All electron beam and friction welds showed toughness lower than parent metals.     

线能量对SAF2507钢焊接接头性能的影响

双相不锈钢的焊接与一般奥氏体不锈钢的焊接有许多不同之处,焊接热循环对接头的组织变化有很大影响,而焊接线能量对焊接热循环有直接的影响。通过采用不同的焊接规范参数,焊接4组试件,并通过微观金相、耐腐蚀倾向试验等方法,分析比较试验结果,评价焊接线能量对00Cr25Ni7Mo4N(2507)焊接接头组织变化、耐腐蚀(点蚀)性能和冲击韧性的影响,为该种钢选择合适的焊接规范参数,提供了依据。     

Effect of Heat Sink and Cooling Mediums on Ferrite Austenite Ratio and Distortion in Laser Welding of Duplex Stainless Steel 2205

In order to control the ferrite and austenite percentage in duplex stainless steel welding, many researchers try to change the laser welding parameters and cooling medium, but ignore to study the influence of heat sink e ect on weld strength. In this work, the e ect of aluminium heat sink and varying cooling medium on the laser welding of duplex stainless steel(DSS) 2205 is studied. The 2 mm thick DSS sheets welded with pulsed Nd: YAG laser welding machine by varying the cooling medium(air and oil) and an aluminium plate used as a heat sink. The welded specimens tested for tensile strength, micro-hardness, distortion, microstructure and radiography analysis. The faster cooling rate in the oil quenching process enhances the ferrite percentage compared with air-cooled samples. But the faster cooling rate in oil quenching leads to more distortion and using aluminium as a heat sink influenced positively the distortion to a small extent. The lower cooling rate in air quenching leads to a higher tensile strength of the welded specimen. The objective of this work is to analyse experimentally the e ect of cooling medium and heat sink in the mechanical and metallurgical properties of laser welded duplex stainless steel.     

双相不锈钢复合钢板焊接

对双相不锈钢复合钢板的焊接特点、焊接材料、焊接方法与焊后热处理进行了重点分析与讨论     

氮对316L不锈钢焊缝力学性能的影响

为研究氮对316L不锈钢焊缝力学性能的影响,采用不同氮质量分数的三种自行研制的焊丝,分别对几组316L不锈钢试板进行钨极氩弧焊(Tungsten inert gas,TIG)焊接,焊后通过金相显微镜和扫描电镜分别观察并分析相应的焊缝组织,采用磁性法测量焊缝的铁素体的质量分数,并对焊缝的拉伸性能、冲击性能等力学性能进行测试。从氮的固溶和焊缝组织的变化等方面综合分析氮对316L不锈钢焊缝力学性能的影响。结果发现,随着氮质量分数的增加,焊缝奥氏体组织明显粗化,铁素体质量分数呈下降趋势;焊缝强度有所提高,且氮质量分数由0.011%增加到0.081%时焊缝强度的平均提高程度小于氮质量分数由0.081%增加到0.10%时焊缝强度的平均提高程度;另外,焊缝的塑性及冲击韧度均有所降低。     

双相钢焊条电弧焊堆焊工艺研究

在不同焊接电流、焊接电压和冷却速度下进行了系统的双相钢焊条电弧堆焊工艺研究,分析了焊接规范对双相钢堆焊金属铁素体含量的影响。试验表明：在双相钢焊接过程中,电弧电压对堆焊金属铁素体含量的影响最大,堆焊金属铁素体含量随着电弧电压的提高而急剧下降。堆焊金属铁素体含量会随着焊接电流的降低及冷却速度的加快而有所提高。经过优化的堆焊工艺下,堆焊金属各项性能均能满足相关标准及技术文件要求。     

不锈钢复合板焊接接头晶间腐蚀失效分析

针对不锈钢复合板焊接接头出现晶间腐蚀裂纹问题,采用光学显微镜、扫描电镜、XRD等技术手段对复合板焊接接头的组织、成分以及相组成进行检测和分析,对焊接工艺规范和热处理制度对焊接接头耐蚀性的影响进行探讨。结果表明,接头焊缝区铁素体含量18．3％,晶粒度9．5级,过渡层焊缝铬的含量9．58％,低于耐蚀性要求;接头产生了σ等硬脆相,这些因素都增大晶间腐蚀敏感性;焊接线能量过大,将降低接头的腐蚀性能;复合板整体消应热处理可以取消。