核级E316L焊条在高温水环境下的均匀腐蚀行为

结合腐蚀失重变化并利用SEM和XRD等手段研究了核级E316L不锈钢焊条熔敷金属在模拟核电一回路水环境中的均匀腐蚀性能。试验结果显示,随着腐蚀周期的增加,腐蚀失重先迅速增加,随后增加趋缓,腐蚀失重速率逐渐减小;而试样表面氧化物颗粒尺寸逐渐增大,氧化膜的主要成分为铁和铬的氧化物;核级E316L不锈钢焊条具有良好的抗均匀腐蚀性能。     

核级316LN不锈钢焊接接头在高温高压水中的腐蚀性能研究

利用扫描电镜、X射线衍射和X射线光电子能谱等分析手段并结合腐蚀增重测量,研究了核级316LN不锈钢焊接接头在高温高压水中的氧化膜变化情况和抗腐蚀性能。结果表明:随着腐蚀周期的增加,腐蚀增重先降低,随后缓慢增加至稳定状态;焊接接头表面氧化膜的主要成分为FeOOH,FeCr_2O_4和Fe_3O_4;316LN不锈钢焊接接头中焊缝区具有与母材区相当的耐均匀腐蚀性能。     

上海焊接器材有限公司

经上海市焊接协会评审，该公司的酸性药皮碳钢焊条、碱性药皮碳钢焊条、E308、E308L、E309、E316、E316L、E347等系列不锈钢焊条产品荣获上海市焊接行业名优产品称号。     

国产核级E308L焊条优化设计与熔敷金属微观特征

对核电站核岛主设备用E308L不锈钢焊条熔敷金属元素影响规律分析、化学成分范围优化设计,并通过优化Creq,Nieq及其比值,使得E308L不锈钢焊条熔敷金属焊态和16 h高温消应力热处理后力学性能达到同一设计要求,E308L焊条熔覆金属以F—A模式凝固,铁素体相含量达到设计最优范围7%~12%,并以较小面积的岛状组织形态均匀分布在奥氏体基体中。该项研究为不锈钢类焊条熔敷金属成分及力学性能优化设计提供思路和借鉴。     

核级不锈钢和铁素体-马氏体耐热钢在400℃/25 MPa超临界水中的腐蚀行为

利用腐蚀增重法,XRD,Raman光谱和SEM研究了核级304不锈钢和铁素体-马氏体耐热钢P92在400℃/25 MPa超临界水中的腐蚀行为.结果表明,2种材料都以均匀腐蚀为主,增重曲线遵循幂指数规律.304不锈钢的腐蚀增重比P92钢低近一个数量级,其氧化膜很薄,局部存在少量的疖状腐蚀.氧化膜主要由Cr_2O_3,α-Fe_2O_3,Fe_3O_4和尖晶石结构氧化物组成.P92钢的氧化膜主要由α-Fe_2O_3,Fe_3O_4和尖晶石结构氧化物组成,表层主要含α-Fe_2O_3.延长腐蚀时间.P92钢表面氧化膜在超临界水中溶解,导致氧化膜形貌由致密的多面体颗粒演化为相互连通的多孔网络结构.     

焊接材料及其生产设备

基于均匀设计方法研究不锈钢焊条的药皮温升；高效低尘结构钢焊条及焊接烟尘影响因素研究；不锈钢焊条E309L和E309Nb的对比；低碳钢芯奥氏体不锈钢代用焊条的研究；合金溜槽堆焊焊条设计及组织分析。     

核电厂稳压器用不锈钢焊条E308L熔敷金属铁素体含量超标的原因分析及处理

文中通过对核电厂稳压器用不锈钢焊条E308L在开展复验时出现的铁素体含量超标问题进行了原因分析,并制订相应的处理和预防措施。结果表明:按照所制订的处理措施分析后的E308L-16焊条用于稳压器的焊接,技术上可行,所制订的预防措施可预防同类问题的发生。     

核用690焊接材料的国产化研究

核用690焊接材料国产化是国家核电计划的重点内容之一,为满足中国飞速发展核电事业的需求,迫切需要国产核用690焊接材料.借助4L不锈钢高压釜、电子天平、扫描电镜等仪器,对自主研发的690焊接材料进行了金相组织、力学性能、晶间腐蚀性能、应力腐蚀性能、均匀腐蚀性能以及缝隙腐蚀性能等的试验研究.结果表明,HS690 焊丝、H...     

质子辐照对AL-6XN在高温高压水中的腐蚀行为影响

利用扫描电镜、能谱分析和X射线衍射研究质子辐照前后的奥氏体不锈钢AL-6XN在高温高压水中的腐蚀行为。结果表明,未辐照的样品在高温高压水中生成了完整的氧化膜,样品增重随着浸泡时间的增加而增加,温度越高腐蚀增重越显著。经过质子辐照后的材料在290℃/10 MPa水中氧化膜发生了严重的溶解,浸泡后样品出现了失重,在550℃/25 MPa超临界水中外层氧化膜发生了剥落,且浸泡时间越长氧化膜剥落越严重。质子辐照不影响氧化膜的元素组成和相结构,同时建议了质子辐照后奥氏体不锈钢在高温水中氧化膜剥落的模型。     

低温用碱性不锈钢焊条E308L-15的研制

文中介绍一种用于-196 ℃低温环境下的碱性奥氏体不锈钢焊条E308L-15。测试了熔敷金属的化学成分、铁素体数、金相组织、耐晶间腐蚀性能、室温强度和-196 ℃低温冲击韧性。结果表明，所开发的E308L-15焊条熔敷金属的金相组织由奥氏体和少量铁素体组成，并且随着熔敷金属氧含量的降低，-196 ℃夏比V形缺口冲击吸收能量增加，讨论了影响熔敷金属低温冲击韧性的因素，提出了提高熔敷金属低温冲击韧性的方法。     

ASTM A240 304H不锈钢SMAW焊接性

针对ASTM A240 304H不锈钢含碳量高的特点,采用E308L焊接304H不锈钢并进行焊接性分析,通过分析得出焊缝FN=8,Creq/Nieq=1.7,焊缝具有良好的抗热裂纹能力,铁素体的存在有利于晶间腐蚀。但是碳含量过高,需要通过限制焊接热输入、层间温度来缩短敏化区停留时间,同时提出了焊接补充措施。     

激光焊接速度对核级不锈钢腐蚀性能的影响

文中对在不同激光焊接速度下得到的核级不锈钢焊接接头进行了核电模拟溶液常温腐蚀试验、点腐蚀和晶间腐蚀试验和高温高压水应力腐蚀试验. 结果表明,随着焊接速度增大,焊接接头维钝电流上升,点蚀电位上升. 在同一焊接接头中,热影响区的耐点蚀性能和晶间腐蚀性能最好,焊接接头整体其次,焊缝区最差. 最低焊速下得到的焊接接头容易产生高温高压水SCC,其SCC裂纹一般从焊道根部的热影响区萌生和扩展.     

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。     

A corrosion study of nickel–copper and nickel–copper–palladium welding filler metals

In an effort to reduce the release of fumes containing carcinogenic Cr⁶⁺ during arc welding of stainless steel, Cr‐free filler metals for welding of SS304 have been developed. Corrosion studies were carried out on 304L stainless steel samples welded with these Cr‐free consumables. The corrosion properties of gas tungsten arc (GTA) and shielded metal arc (SMA) welds fabricated with Ni? Cu and Ni? Cu? Pd consumables were found to be comparable to those of welds fabricated with SS308L, the standard filler metal used with SS304. Although the breakdown potentials of the welds made using both welding processes were lower than that of the SS308L GTA weld, the repassivation potentials of these welds were much higher. Generally, the repassivation potential is a more conservative measure of susceptibility to localized corrosion. Accordingly, the Ni? Cu and Ni? Cu? Pd welds were more resistant to crevice corrosion than SS308L welds. The addition of a small amount of Pd improved the corrosion resistance relative to Ni? Cu welds, which is consistent with previous studies from specially‐prepared button samples and bead‐on‐plate samples. Other corrosion studies such as creviced and uncreviced long time immersion, atmospheric exposure, and slow strain rate testing suggest that Ni? Cu? Pd filler metal can be a potential replacement for the conventional SS308L filler metal for joining SS304.     

影响P92钢焊缝冲击韧性的焊接工艺

P92钢是新型铁素体耐热钢,已广泛应用于超(超)临界燃煤发电机组。相比其他铁素体耐热钢,P92钢具有更高的高温强度和蠕变性能,其抗热疲劳性、热传导系数和热膨胀系数远优于奥氏体不锈钢,抗腐蚀性和抗氧化性优于其他9%Cr的铁素体耐热钢。P92钢的焊接技术已较为成熟,但其焊接接头易出现焊缝冲击韧性偏低的问题。影响P92钢焊缝金属冲击韧性的主要因素是焊接热输入。细焊条、薄焊层、多层多道焊,适当的预热温度、层间温度,足够的高温回火温度和恒温时间,是保证焊缝冲击韧性的有效措施。     

Korrosionsbeständigkeit von Verbindungen von Rohren aus nichtrostenden Stählen in Wässern

Corrosion of joints for stainless steel tubes in water The most important commonly used joining techniques for stainless steel tubes which are used for the transport of water and gases are welding and brazing. With corrosion attack by dry gases, both connections are resistant against corrosion. However, in water and aqueous condensates limits of application exist with regard to the corrosion resistance. The corrosion resistance of weld connections with stainless steel tubes is diminished by

• – annealing colours (oxide films) and scale layers in the weld area;
• – changes in the microstructure adjacent to the welds (sensitization of the stainless steel material);
• – surface finish of weld seams after welding;
• – welding faults resulting from bad handling and workmanship.

Type and extent of corrosion damage occurring on weld connections with decreased corrosion resistance depend on the composition of the water and condensates, mainly on their chloride content. Typical examples for the causes of degraded corrosion resistance of weld connections, and possible types of corrosion attack, namely pitting, crevice corrosion, and stress corrosion cracking and their mechanisms are described. Furthermore, measures are shown by which the corrosion resistance of weld connections with stainless steel tubes can be increased. Joints of stainless steel tubes by hard soldering with capillary fittings are endangered by knife line attack at the phase boundary between the stainless steel and solder (interfacial corrosion). Knife line attack means in this context the loss of adhesion between steel and hard solder. The severity of the corrosion risk, in particular the incubation time until the occurrence of the corrosion damage, depends on the water quality, mainly on chloride concentration, and pH. The press fitting with non-metallic gasket is a relatively new joining system, and it is used in the cold and warm water domestic installation. This joining technique is described. For domestic water distribution, an installation system with tubes and press fittings made of steel grade AISI 316 SS has been developed. This system is resistant to corrosion attack in potable water of usual composition, and it is already applied in-service in a considerable extent. Other joining systems are stainless steel weld fittings, threaded screw fittings, and compression couplings with cutting or clamping rings. They are used mainly in industrial installations.     

12Cr2AlMoV钢焊接热处理实验研究

作为耐硫化氢腐蚀的国产12Cr2AlMoV钢，当采用与其匹配的R317焊条焊接时，为防止焊接裂纹，焊前应预热，为抑制“熔合区”产生“铁素体带”，焊后需高温回火，通过可焊性试验以及焊接工艺评定，实验出了该钢最佳焊接热处理规范。     

Welding Heat Input Influence on UNS S82441 Lean Duplex Stainless Steel Corrosion Resistance Assessed by Scanning Vibrating Electrode Technique (SVET)

The precipitation of the intermetallic phases can impair mechanical and corrosion properties. In the case of lean duplex stainless steels, they present solidification mode as primary ferrite, with austenite precipitation in the solid state, during cooling. This means the heat-affected zone balanced microstructure can be changed during the welding by the cooling rate, which is associated to the welding heat input, the thickness of the plate and the physical properties of the material. This work intends to present the influence of welding heat input on the corrosion resistance of UNS S82441 lean duplex stainless steel. The gas metal arc welding process was used to make the weld beads, using ER2209 as filler metal, which characterizes a dissimilar welded joint. The corrosion resistance of these specimens was analyzed through scanning vibrating electrode technique. It was observed that welding heat input variation distinctly influences corrosion in different zones of the weld beads over the specimen exposure time. The weld bead under intermediate welding heat input showed the highest corrosion rate and the one under the highest welding heat input, the lowest corrosion rate intensity.     

Microstructure and Mechanical Behavior in Dissimilar SAF 2205/API X52 Welded Pipes

The welding of a duplex stainless steel SAF 2205 DSS(UNS 31803) and high strength low alloy steel API X52 by shielded metal arc welding process was conducted using two different filler metals,the duplex E2209 and austenitic E309 grade.The microstructures of the dissimilar metal joints have been investigated by optical microscopy,scanning electron microscopy,energy-dispersive spectroscopy(EDS) and X-ray diffraction.EDS analysis at the interface X52 weld metal showed an evident gradient variation of Cr and Ni between boundaries of fusion and type II,where the highest hardness value was recorded.Tensile strength and toughness values of the weld metal produced by E309 electrode are slightly higher than those of the weld metal produced by E2209 electrode.Potentiodynamic polarization tests of different regions of the welded joints evaluated in 3.5%NaCl solution exhibit a high corrosion resistance of both weld metals.     

核电设备不锈钢堆焊层的铁素体含量

针对化学分析法和磁性法测得的核电设备不锈钢堆焊层铁素体含量的差异,以及焊接工艺参数和焊后热处理对铁素体含量的影响规律,采用3种焊接方法在16MND5低合金钢上堆焊309L+308L进行试验研究。结果表明:磁性法和化学分析法得到的铁素体含量数据之间存在一定的差距;道间温度和焊接电流的提高会使铁素体含量降低;焊后热处理会降低铁素体含量,热处理温度提高和热处理时间的延长会使铁素体含量进一步降低。