高压氢环境奥氏体不锈钢焊件氢脆研究进展

奥氏体不锈钢焊件是高压氢系统中重要的承载结构,其长期服役在高压高纯氢气环境中会出现塑性损减、疲劳裂纹扩展速率加快等氢脆现象,导致高压氢系统存在安全隐患。因此,为保障高压氢系统的安全运行,研究高压氢环境奥氏体不锈钢焊件的氢脆具有重要意义。本文首先介绍奥氏体不锈钢焊件中氢的两种来源,随后讨论评价材料氢脆敏感性的静态实验方法和动态实验方法,其次概述当前主流的氢脆机理,然后着重分析内部因素及外部因素对奥氏体不锈钢焊件氢脆敏感性的影响,最后归纳并总结五种典型的奥氏体不锈钢焊接工艺对焊件微观组织的影响,并进一步探讨相应焊件的氢脆敏感性。基于上述分析,针对奥氏体不锈钢焊件氢脆性能研究现状及发展趋势提出了若干建议。     

不锈钢表面阻氢涂层研究进展

不锈钢是高压氢系统的常用材料,在氢能储输技术中发挥重要作用,但高压氢环境引起的塑性降低、疲劳裂纹扩展速率加快等不锈钢氢脆问题,严重阻碍了氢能的产业化发展,在不锈钢材料表面制备阻氢涂层是解决不锈钢氢损伤问题的重要手段之一。本文首先综合介绍了典型涂层材料的应用特点及阻氢性能,探讨了制备工艺对涂层阻氢性能的影响、不同涂层材料的阻氢机理,并分析了涂层阻氢性能影响因素,之后总结了涂层阻氢性能评价方法及各种评价方法的优势与不足,并根据各种评价方法的技术特点,指出每种方法的适用范围。最后,基于阻氢涂层研究进展,文章提出以开发新型涂层结构为研究重点,同时加快新型涂层材料的探索,并重点关注涂层氢环境原位性能评价方法的研究。     

高温高压条件下不锈钢的氢损伤

综述了高温高压条件下氢致不锈钢损伤的研究进展情况,重点介绍了不锈钢力学性能和微观结构的变化,并就压力和温度对氢损伤敏感性影响作了简单的讨论。     

氯离子与冷却水系统中不锈钢的腐蚀

综述了有关氯离子对冷却水系统中不锈钢腐蚀研究的最新进展,涉及冷却水中氯离子引发不锈钢孔蚀、缝隙腐蚀和应力腐蚀开裂的机理,氯离子的限度,以及影响水中不锈钢腐蚀的其他因素.对如何应对冷却水中氯离子的负面效应提出了见解.     

锁紧环换热器耐蚀层堆焊工艺研究

锁紧环式换热器在高温、高压、临氢和硫化氢环境条件下工作,需在其内部堆焊不锈钢耐蚀层。但不锈钢耐蚀层的堆焊是制造中的技术难点,堆焊材料选择不当或堆焊工艺不合理会产生堆焊层剥离问题,所以解决堆焊层的抗剥离问题就成为锁紧环制造中的技术关键。通过对不锈钢耐蚀层产生剥离问题的影响因素进行焊接性分析和工艺研究,确定了最佳工艺匹配,成功地完成了耐蚀层堆焊。     

粘接用加成型液体硅橡胶的制备与性能研究

研制了一种粘接不锈钢用、耐水煮,120℃、10 min完全固化的食品级加成型液体硅橡胶。制备了一种乙烯基环氧硅氧烷低聚物增粘剂,研究了增粘剂用量、气相二氧化硅、含氢硅油的活性氢含量,含氢硅油中的硅氢与乙烯基硅油中的乙烯基的物质的量比[n(SiH)/n(SiVi)]对加成型硅橡胶的粘接性等性能的影响。结果表明,选用10 000 m Pa·s乙烯基硅油,增粘剂用量1.5%,含氢硅油活性氢质量分数0.75%,n(SiH)/n(SiVi)=1.3时,制备的不锈钢粘接用加成型液体硅橡胶性能优异。     

回用水中氨氮对不锈钢耐腐蚀性的影响

城市污水回用是缓解工业用水紧张的有效途径.作者分析了城市污水二沉池出水富含的NH4 -N对冷却水系统中316L不锈钢耐腐蚀性的影响,用阳极极化曲线法和电化学阻抗谱法研究了氨氮对316L不锈钢的影响.结果显示,NH4 -N对点蚀电位有较大影响,溶液中氨氮的存在使不锈钢的成膜过程受到影响,且阻抗值明显降低.     

12SiMoVNb低合金钢在小氮肥厂的应用

该厂在两套(?)600自成系统的改造时,其合成塔出口至度热锅炉的高压管线采用了国产抗氢高压无缝管(材质为12SiMo VNb).文章认为,12SiMoVNb低合金钢可替代价格昂贵的1Cr18NigTi不锈钢用于小氮肥厂的合成氨节能技改.该钢种具有耐高压、中温和抗氢、氮、氨等性能.     

防氢型变送器原理及应用

从炼厂加氢装置变送器的使用现状出发,分析变送器的氢脆现象,提出解决氢渗透的途径.研制出了一种双层镀层的法兰变送器,从根本上解决了氢渗透问题.该工艺是在SUS 316L不锈钢隔离膜片基材上先镀一层金,然后在金镀层表面再镀一层陶瓷膜.经使用该变送器防氢效果较好.     

火电厂氢冷器在线清洗风险性研究

针对迎峰度夏期间某电厂氢冷器结垢急需进行清洗的实际情况,设计了相应的清洗方案,对清洗方案的效果和风险性进行研究,以便为同类型机组氢冷器清洗提供参考和借鉴。结果证明清洗方案对氢冷器垢层有一定的清洗效果,并对系统中B30白铜、TP316L不锈钢、海军黄铜、碳钢等金属材质以及氯丁橡胶等非金属材质均无明显的腐蚀加速作用,清洗时可保证氢冷器和整个循环冷却水系统的安全及稳定运行。     

Zn离子注入对核电站结构材料腐蚀性能的研究进展

锌离子注入技术是核电厂用于抑制职业辐射照射的有效手段,在减少职业辐射照射剂量的同时,也增加了核电站结构材料的耐腐蚀性能。文章综述了锌离子注入技术对核电站的结构材料不锈钢,镍基合金腐蚀性能研究的进展,主要通过光电化学方法和半导体性质进行分析锌离子对不锈钢镍基合金耐腐蚀性。     

Vaporized Hydrogen Peroxide and Ozone Gas Synergistically Reduce Prion Infectivity on Stainless Steel Wire

Prions are infectious agents causing prion diseases, which include Creutzfeldt–Jakob disease (CJD) in humans. Several cases have been reported to be transmitted through medical instruments that were used for preclinical CJD patients, raising public health concerns on iatrogenic transmissions of the disease. Since preclinical CJD patients are currently difficult to identify, medical instruments need to be adequately sterilized so as not to transmit the disease. In this study, we investigated the sterilizing activity of two oxidizing agents, ozone gas and vaporized hydrogen peroxide, against prions fixed on stainless steel wires using a mouse bioassay. Mice intracerebrally implanted with prion-contaminated stainless steel wires treated with ozone gas or vaporized hydrogen peroxide developed prion disease later than those implanted with control prion-contaminated stainless steel wires, indicating that ozone gas and vaporized hydrogen peroxide could reduce prion infectivity on wires. Incubation times were further elongated in mice implanted with prion-contaminated stainless steel wires treated with ozone gas-mixed vaporized hydrogen peroxide, indicating that ozone gas mixed with vaporized hydrogen peroxide reduces prions on these wires more potently than ozone gas or vaporized hydrogen peroxide. These results suggest that ozone gas mixed with vaporized hydrogen peroxide might be more useful for prion sterilization than ozone gas or vaporized hydrogen peroxide alone.     

Numerical and experimental study of the effect of gas evolution in electrolytic pickling

As part of a progressive approach to model the electrolytic pickling process, this paper focuses on the important aspect of hydrogen and oxygen gas evolution on the electrodes and on the steel strip being pickled. The system considered consists of type 316 stainless steel pickled in aqueous sodium sulphate, with lead anodes and stainless steel cathodes. The mathematical model is two-dimensional steady-state, and includes the differential equations describing the effect of migration, giving the potential and current fields, and the Tafel kinetic rate expressions for hydrogen and oxygen gas generation. Experiments were conducted to obtain a better understanding of the process and for model validation. Good agreement between the experimental measurements of the global current efficiency and the model predictions was obtained.     

Asymmetric Pd---Ag/stainless steel catalytic membranes for methane steam reforming

Pd-Ag/porous stainless steel asymmetric membranes were prepared by successive palladium and silver platings in electroless hydrazine baths, followed by a thermal treatment in hydrogen of the as-deposited membranes above the Tamman temperatures for the alloy formation. The prepared membranes were permselective toward hydrogen separation. A membrane reactor made of stainless steel was designed to perform methane steam reforming. At mild reaction conditions, methane conversion is significantly enhanced by partial removal of hydrogen from the reaction location as a result of diffusion through the Pd-based membrane. These effects were examined under a variety of experimental conditions.     

Kinetics of hydrogen evolution reaction on a stainless steel electrode

The kinetic parameters for the hydrogen evolution reaction on a stainless steel substrate have been obtained from a study of the steady-state polarization curves as well as the galvanostatic transients. The high Tafel slope obtained in the steady-state polarization measurements was ascribed to the presence of an oxide film present on the surface of the stainless steel electrode.     

Electrochemical corrosion characteristics of type 316 stainless steel in simulated anode environment for PEMFC

The corrosion behavior of type 316 stainless steel in simulated anode environment for proton exchange membrane fuel cell (PEMFC), i.e., dilute hydrochloric acid solutions bubbled with pure hydrogen gas at 80 °C, was investigated by using electrochemical measurement techniques. The main purpose is to offer some fundamental information for the use of stainless steels as bipolar plate material for PEMFC. Both polarization curve and electrochemical impedance spectroscopy (EIS) measurements illustrate that 316 stainless steel cannot passivate spontaneously in the simulated environments. The absorbed (and/or adsorbed) hydrogen atoms from cathodic corrosion reactions on the steel surface may deteriorate the passivity and corrosion resistance. The oxidation of these hydrogen atoms gives rise to a second current peak in the anodic polarization curve, and the current increases with immersion time. EIS spectra also reveal that a porous corrosion product layer formed on the steel surface during the active dissolution in the test solutions. 316 stainless steel exhibits the similar corrosion behavior in sulfate ions containing dilute hydrochloric acid solution.     

陶瓷涂层对固体氧化物燃料电池连接体材料表面改性的研究

铁素体不锈钢是应用前景最好的中温固体氧化物燃料电池（SOFC）连接体材料之一,然而高温抗氧化能力不足和Cr元素的挥发严重了影响铁素体不锈钢连接体材料的长期稳定性。解决该问题的最有效的途径是在铁素体不锈钢连接体表面制备陶瓷保护涂层,达到改善铁素体不锈钢的高温抗氧化性能和抑制Cr元素的挥发的目的。本文概述了采用陶瓷涂层对铁素体不锈钢连接体材料进行表面改性的研究现状。     

不锈钢封头在低温临氢工况下的开裂分析

利用硬度检测和马氏体含量检测、金相组织及现场裂纹观察等手段,对某低温临氢奥氏体不锈铜凸形封头的开裂原因进行了分析并进行了理论研究。认为该封头的开裂属于氢致裂纹（HIC）,缘于冷加工形变、氢在不同温度下的扩散以及低温等因素的交互作用。冷加工变形所造成的马氏体相变、位错密度的升高是造成氢致裂纹的主要原因;残余应力为裂纹的形成与扩展创造了有利条件;氢在马氏体中的溶解度随温度变化而不同,从-50℃至-100℃溶解度降低幅度较大,析出的氢是造成封头开裂的直接因素。亚稳定型奥氏体不锈钢元件在冷加工成形后进行固溶处理是降低其氢脆敏感度的有效手段。