焊丝对T2紫铜/316L不锈钢GTAW接头组织及性能的影响

采用钨极氩弧焊,分别填充纯铜焊丝和307Si焊丝对T2紫铜/316L不锈钢异种金属进行对接焊,探究焊丝对铜/不锈钢异种金属接头微观组织、力学性能和耐蚀性的影响.结果表明,铁-铜液相分离对焊缝组织的形成起主导作用,但由于过冷度不同,填充两种焊丝制备焊缝的液相分离程度不同:铜焊丝制备焊缝中生成了初次液相分离富铁球,其内部又...     

空间多位置摆动激光填丝焊接熔池动态行为及焊缝成形

以316L奥氏体不锈钢管道为研究对象,在摆动激光焊接研究基础上,对管道多位置激光填丝焊接熔滴过渡和焊缝成形展开研究,分析焊接熔池动态特征,优化各位置区间工艺参数,进而实现管道全位置激光焊接.结果表明,摆动激光束周期性的作用于填充焊丝,产生的反冲压力能够促进熔滴过渡,使得焊丝始终以"液桥"形式向熔池过渡;同时摆动激光增强了熔融金属侧向流趋势,提高熔池界面表面张力,削弱空间多位置下重力对熔池形貌的影响,保证各空间位置熔池均能稳定存在,焊缝成形连续均匀.     

316L不锈钢薄板埋弧焊工艺

论述了316L不锈钢的焊接性.选用ER316L焊丝配用SJ601焊剂,进行了316L薄板埋弧焊的焊接工艺评定试验.用经过评定合格的SAW工艺,对厚度分别为6 mm和5 mm的316LMA水解塔的纵焊缝和环焊缝进行施焊.焊后依据JB/T4730.2-2005标准进行了RT检验,其一次合格率为100%.     

316L不锈钢管道免充氩打底焊

针对316L不锈钢小口径管道打底过程中的背面保护问题,分别采用熔化极气体保护焊配合相应的药芯焊丝打底并盖面,以及钨极氩弧焊配合药芯焊丝打底+焊条电弧焊盖面两种焊接方法,对规格为φ108 mm×10 mm的316L不锈钢管道进行对接焊.并分别对焊接接头进行射线检测、金相观察、力学性能检测及抗晶间腐蚀性能检测.结果表明,使用药芯焊丝对小口径316L不锈钢管道进行焊接时管内不充氩气可以达到实用要求.     

焊丝中钒对316L/T91焊缝显微组织及力学性能的影响

采用自行熔炼的4种焊丝(钒元素质量分数分别为0、0.2％、0.4％和0.6％),使用钨极氩弧焊(TIG)对316L奥氏体不锈钢和T91马氏体不锈钢进行了焊接,探究了钒元素对焊接接头组织和性能的影响.研究结果表明,4种焊丝所得的焊缝组织都是由奥氏体加δ铁素体组成,随着焊丝中钒元素含量的增加,焊接接头的焊缝组织变得更加细小...     

316L不锈钢管现场全位置焊接

针对316L不锈钢管水平固定全位置现场焊接时,难以在焊缝背部充氩气保护、视线受阻不易操作、质量不稳定等问题,研发了免充氩不锈钢焊丝、管内送丝的钨极氩弧打底焊,分段跳焊的CO₂气体保护焊填充及盖面焊,并制定了相应的焊接工艺参数和具体的操作方法。采用该工艺对D219 mm×4 mm的316L不锈钢管进行管-管对接焊。试验结果表明,采用该工艺指导实际生产操作简单;获得的焊缝成形良好,焊缝外观质量检查和焊缝探伤检测合格,满足了现场高效高质生产的要求,对316L不锈钢管现场全位置施工具有指导意义和应用价值,在复杂的工艺管道施工和操作空间狭小的作业时其优点更为突出。     

L80-1钢基管与SUS304钢端环焊接工艺

研究了防砂筛管基管L80 -1低合金钢与端环SUS304不锈钢的焊接工艺,采用TIG焊方法,选用ER316L焊丝,采用小电流、低电压、窄焊道快速焊和多层焊等工艺方法,控制焊缝的成形系数,解决了L80 -1母材热影响区淬硬和焊缝的弧坑裂纹等问题,保证了筛管的焊接质量.     

焊接工艺参数对E309L药芯焊丝焊缝金属铁素体数的影响

采用铁素体测试仪、Schaeffler图及WRC-1992图3种测试方法,研究了不同焊接工艺参数对E309L药芯焊丝焊缝金属铁素体数(Ferrite number, FN)的影响。结果表明,焊缝金属FN随焊接电参数的改变变化最大,气体流量居中,焊丝伸出长度最小;适当地增大焊丝伸出长度和气体流量可以降低FN;焊缝金属中N元素对气体流量、焊丝伸出长度的变化比较敏感,WRC-1992图法因考虑了N元素的作用,测试结果更准确,而铁素体测试仪法适合测试正常焊接工艺参数下的FN;随着焊接电参数、焊丝伸出长度、气体流量的增大,Schaeffler图法测试焊缝金属FN均逐渐减小。     

相对流速对316L钢焊缝在液态铅铋合金中腐蚀行为的影响

在核工业领域,316L不锈钢因其优异的性能常被作为核用钢种,液态铅铋合金常作为加速器次临界驱动系统(ADS)的冷却剂,高速流动的液态铅铋合金(LBE)会对316L不锈钢焊缝造成氧化腐蚀,同时氧化腐蚀后的产物也会对液态LBE造成污染,所以研究316L不锈钢焊缝在液态铅铋合金中的腐蚀行为具有重要意义. 文中对比研究了使用母材作为焊丝进行TIG焊的316L不锈钢焊缝在550 ℃动态(相对流速为1.70,2.31,2.98 m/s)液态LBE中的耐腐蚀性能,试验时间为1 500 h. 结果表明,三组试样都生成了双氧化层,外氧化层主要为Fe₃O₄,内氧化层主要为FeCr₂O₄,内氧化层相对于外氧化层较致密;随着流速的提高,元素的传质过程变快,氧化腐蚀加剧,内氧化层增厚.     

太阳能保温水箱内胆A焊缝的焊接

针对太阳能保温水箱新材料SUS444(00Cr18Mo2)内胆A焊缝的焊接问题,采用了手工钨极氩弧焊,科学选择ER316L作为填充焊丝,重点防范焊接污染及尽可能采用小线能量、小规范施焊,不仅解决了A焊缝焊接的晶间腐蚀和脆化问题,而且很好满足内胆耐腐蚀、保温效果好的要求,保持水箱水质清洁。     

Effect of Austenitic and Austeno-Ferritic Electrodes on 2205 Duplex and 316L Austenitic Stainless Steel Dissimilar Welds

This study addresses the effect of different types of austenitic and austeno-ferritic electrodes (E309L, E309LMo and E2209) on the relationship between weldability, microstructure, mechanical properties and corrosion resistance of shielded metal arc welded duplex/austenitic (2205/316L) stainless steel dissimilar joints using the combined techniques of optical, scanning electron microscope, energy-dispersive spectrometer and electrochemical. The results indicated that the change in electrode composition led to microstructural variations in the welds with the development of different complex phases such as vermicular ferrite, lathy ferrite, widmanstatten and intragranular austenite. Mechanical properties of welded joints were diverged based on compositions and solidification modes; it was observed that ferritic mode solidified weld dominated property wise. However, the pitting corrosion resistance of all welds showed different behavior in chloride solution; moreover, weld with E2209 was superior, whereas E309L exhibited lower resistance. Higher degree of sensitization was observed in E2209 weld, while lesser in E309L weld. Optimum ferrite content was achieved in all welds.     

Microstructure and mechanical properties of dissimilar welds between 16Mn and 304L in underwater wet welding

Dissimilar joint between 304L austenitic stainless steel and low-alloy steel 16Mn was underwater wet welded using self-shielded nickel-based tubular wire. Microstructure, mechanical properties and corrosion behaviour of dissimilar welded joints were discussed. Ni-based weld metal was fully austenitic with well-developed columnar sub-grains. Type II boundary existed between Ni-based weld metal and ferritic base metal in underwater welds similar to that in air welds. Major alloying elements distributed non-uniformly across the austenitic weld metal/16Mn interface. Maximum hardness values in wet welding appeared in a coarse-grained heat-affected zone at the 16Mn side, which possessed very low impact toughness. Underwater Ni-based welded joints fractured at Ni-based weld metal under tensile test. Ni-based weld metal had favourable corrosion resistance similar to 304L base metal.     

基于神经网络的316L不锈钢激光焊焊缝形貌预测

在316L不锈钢的激光焊接过程中,其焊接工艺参数直接影响焊缝的形貌,建立焊接工艺参数与焊缝几何形状之间的关系对于优化焊接工艺参数,降低焊接成本非常重要. 根据316L不锈钢焊缝二维不光滑轮廓形貌特点,采用分段函数思想,分别使用Hermite插值和最小二乘拟合的方法描述焊缝轮廓,构建广义回归神经网络焊缝二维形貌预测模型. 结果表明,采用Hermite插值的方法能够获得更准确的焊缝形貌,其平均相对误差为?3.49%. 该模型为316L不锈钢激光焊焊缝预测提供一种有效方法.     

氦离子辐照对316L钢焊缝微观结构及性能影响

316L不锈钢作为压水堆候选结构材料,在服役过程中需要承受辐照效应. 为了探明辐照对316L焊缝微观结构及性能的影响及作用机制,系统研究了经氦离子辐照后316L钢焊缝表面形貌、微观组织结构、显微硬度及电化学腐蚀性能的变化规律. 结果表明,150 keV氦离子辐照后试样表面产生大量细小的孔洞,这导致试样耐腐蚀性能降低,母材和焊缝金属腐蚀电流密度分别增加5.42 × 10?5与5.91 × 10?5 A/cm2. 辐照导致试样内部出现氦泡、位错等缺陷,这些缺陷使得试样产生辐照肿胀和辐照硬化现象,母材与焊缝肿胀率分别为0.103%与0.181%,显微硬度分别提高2.33与2.55 GPa. 通过EBSD测试方法证实,焊缝金属晶粒尺寸较大,使得其抗辐照性能相比316L钢稍差.     

A comparison of hydrogen embrittlement susceptibility of two austenitic stainless steel welds

Slow displacement rate tensile tests were carried out to assess the effect of hydrogen embrittlement on notched tensile strength (NTS) and fracture characteristics of AISI 316L and 254 SMO stainless steel (SS) plates and welds. 254 SMO generally exhibited a better resistance to hydrogen embrittlement than 316L. The strain-induced transformation of austenite to martensite in the 316L SS was responsible for the high hydrogen embrittlement susceptibility of the alloy and weld. Sensitized 254 SMO (i.e., heat-treated at 1000 °C/40 min) base plate and weld comprised of dense precipitates along grain boundaries. Interfacial separation along solidified boundaries was observed with the tensile fracture of 254 SMO weld, especially the sensitized one. Dense grain boundary precipitates not only reduced the ductility but also raised the susceptibility to sulfide stress corrosion cracking of the sensitized 254 SMO plate and weld.     

CO2环境下油酸咪唑啉对X65钢异种金属焊缝电偶腐蚀的抑制作用研究

研究了X65管线钢与316L不锈钢、Inconel 625双金属复合管的异种金属焊缝在CO2环境下的电偶腐蚀行为,以及油酸咪唑啉的缓蚀作用。结果表明,随着电偶电位差的增大,异种金属焊缝的腐蚀速率明显升高,并且都显著高于母材。添加油酸基咪唑啉缓蚀剂能降低异种金属焊缝在CO2环境下的均匀腐蚀速率。但是,当缓蚀剂浓度添加较低时,异种金属焊接试样的碳钢一侧出现了严重的沟槽腐蚀或密集的点蚀坑;进一步增加缓蚀剂浓度才能消除沟槽腐蚀现象。讨论了缓蚀剂对异种金属焊缝电偶腐蚀的抑制机理,该项研究可为异金属焊接接头处的腐蚀防护提供借鉴。     

合金元素对铜/钢接头连接机理及性能的影响

采用HS201实心焊丝、Cu-Si药芯焊丝、Cu-Ni药芯焊丝3种不同的焊接材料对T2铜和304不锈钢异种金属进行了熔化极气体保护焊接试验.主要研究了合金元素(Si,Ni)对T2铜/304不锈钢连接机理及焊接接头微观组织、力学性能的影响.结果表明,采用3组焊丝得到的焊缝成形良好,且焊接接头的横截面均未出现明显的宏观缺陷...     

填充金属对2205双相不锈钢TIG焊接头组织与性能的影响

采用TIG工艺,选取焊接电流为100 A,分别选用直径为2. 0 mm的ER308,Ni317焊丝对2205双相不锈钢进行双面焊,研究了焊接接头的金相组织、拉伸性能、显微硬度和腐蚀性能。结果表明,在焊接电流为100A时,在选取的两种焊丝条件下,焊缝组织均为枝晶状,填中金属中Ni元素有促进奥氏体形成作用,采用ER308焊丝得到的接头具有更好的塑性及抗拉强度,采用Ni317焊丝得到的接头比采用ER308焊丝得到的接头更耐腐蚀。     

Microstructure and mechanical properties of underwater friction taper plug weld on X65 steel with carbon and stainless steel plugs

Underwater friction taper plug welding for X65 pipeline steel was performed using Q345 structural steel and 316L stainless steel plugs. Weld microstructures, defects formation and mechanical properties were investigated. Using Q345 plugs can produce defect free and overmatching welded joints whose impact toughness was also favourable. Lower bainite and lath martensite in the weld zone resulted in high hardness with maximum value up to 418?HV10. Using 316L plugs can significantly reduce weld zone hardness due to austenite dominated microstructure. Microcracks can easily emerge at and may propagate along γ–δ phase boundaries to form macrocracks. Intermittent cracks were found along the bonding interface of all the 316L plug welds, which should be caused by the relief of the residual stress.