海洋环境下不锈钢材料耐腐蚀性能的试验研究

选取碳钢结合耐高温涂层、06Cr18Ni11Ti、14Cr17Ni2、00Cr22Ni5Mo3N共四种材料,制成试样,通过金相试验、自然腐蚀电位试验、应力腐蚀试验、盐雾加速腐蚀试验等,分析材料在海洋环境下的耐腐蚀性能。结果表明:三种不锈钢试样的腐蚀失重量比较接近,都不到碳钢结合耐高温涂层试样的腐蚀失重量的10%;00Cr22Ni5Mo3N的耐腐蚀性最好,06Cr18Ni11Ti略逊于00Cr22Ni5Mo3N,14Cr17Ni2更逊于06Cr18Ni11Ti。     

00Cr18Ni12Mo2Ti不銹鋼的埋弧自动焊

在化工,炼油等机械制造厂中常常会遇到一些耐酸不锈钢的焊接。常用的不锈綱板是0Cr18Ni9Ti型,但根据工作介质的不同,在某些容器及管子的材质选择上要求比0Cr18Ni9Ti不锈钢具有更高的抗晶间腐蚀性能。众所周知,00Cr18Ni12Mo2Ti不锈钢的抗日间腐蚀能力相当优越,它是在0Crl8Ni9Ti基础上适当提高铬、镍含量,并加入2～3％的钼,藉此提高了该种钢材在无机酸、有机酸、碱、盐中的抗蚀性和耐热性。钢中还     

0Cr18Ni9、1Cr13和1Cr17不锈钢在熔融LiCl-5%Li2O中的腐蚀行为

采用浸没法分别研究了0Cr18Ni9、1Cr13和1Cr17三种不锈钢材料在700℃LiCl-5%Li2O(质量分数)熔融盐中的腐蚀行为.结果表明:0Cr18Ni9和1Cr13不锈钢的腐蚀产物主要为LiFeO2和LiCrO2,1Cr17的腐蚀产物主要由LiFeO2、LiFe5O8和LiCrO2组成;三种钢的腐蚀速率均随时间的延长而增大,并且1Cr13的腐蚀速率明显大于1Cr17和0Cr18Ni9的;在试验条件下,1Cr17铁素体钢和0Cr18Ni9奥氏体钢的耐蚀性能相当,均优于1Cr13马氏体钢.     

00Cr18Ni12Mo2Ti不锈钢的埋弧自动焊

在化工,炼油等机械制造厂中常常会遇到一些耐酸不锈钢的焊接。常用的不锈钢板是0 Cr 18 Ni 9 Ti型,但根据工作介质的不同,在某些容器及管子的材质选择上要求比0 Cr 18 Ni 9 Ti不锈钢具有更高的抗晶间腐蚀性能。众所周知,00 Cr 18Ni 12 Mo 2Ti不锈钢的抗晶间腐蚀能力相当优越,它是在0 Cr 18 Ni 9 Ti基础上适当提高铬、镍含量,并加入2～3％的钼,藉     

耐酸钢1Cr18Ni9Ti的氧氮化

1.耐酸钢表面硬化存在的困难 1Cr18Ni9Ti是一种铬-镍型不锈钢,它有较好的耐蚀性,能抵抗各种酸类的腐蚀,故又称不锈耐酸钢.它有良好的塑性、韧性和焊接性,但硬度较低、耐磨性较差。随着工业生产的发展,对1Cf18Ni9Ti钢在使用上提出了更高的要求,如化工设备、航空工业、石油机械、造船、医疗器械等都要求材料有较高的抗腐蚀性,又要有高的硬度。而1Cr18Ni9Ti钢是一种     

不锈钢阳极氧化

一、工艺参数: 介质:20～30%硫酸 0.1%钼酸钠;电流密度:10～20毫安/厘米~2;处理时间:10～20分钟;处理温度:室温;阳极:不锈钢;阴极:铅板。二、处理效果: 1.阳极氧化处理后的不锈钢,其显著的特点是大大地提高了它的耐蚀性。例如1Cr18Ni9Ti钢在沸腾的5%硫酸中是不耐蚀的,腐蚀速率大于10毫米/年。我们将该钢种试样进行阳极氧化处理后,在同样的条件下经过805小时试验后仍未发生腐蚀,试样表面仍光亮如新。图1表示阳极氧化处理后的1Cr18Ni9Ti钢和未经阳极氧化处理的1Cr18Ni12Mo2钢在各种浓度的硫酸中的耐蚀性。图2表示阳极氧化和未经阳极氧化的1Cr18Ni9Ti钢在硫酸中的腐蚀速率。     

ZrO_2陶瓷在H_2O_2介质中的摩擦学性能研究

在MMW-1立式万能摩擦磨损试验机上对ZrO2陶瓷球与1Cr18Ni9Ti不锈钢环在不同体积分数的H2O2介质中的摩擦磨损行为进行研究,并通过激光干涉表面形貌测量仪考察球试样与环试样的磨损表面形貌,对比分析摩擦因数、磨损量、摩擦副的磨损表面形貌的变化规律。结果表明,在不同体积分数的H2O2介质中,ZrO2/1Cr18Ni9Ti摩擦配副的摩擦学性能存在着明显差异;低浓度H2O2溶液在磨损过程中对不锈钢材料具有类似抛光打磨的过程,导致腐蚀磨损表面较为光滑;一定浓度的H2O2介质能有效地起到改善摩擦磨损特性的作用。     

用于芒硝矿一种经济的耐腐蚀泵的探讨

言引生产芒硝最主要的工艺流程之一是芒硝未结晶前高温Na_2SO_4水溶液的强制循环,其过程需要多台水泵。采用一般水泵在这种腐蚀性介质下工作,腐蚀严重,泄漏利害,使用周期极短;采用不锈钢或优质不锈钢材料如1Cr18Ni9Ti、1Cr13、2Crl3、1Cr18Ni12Mo2Ti、Cr15Mo3等来制造水泵,又不太理想。因为首先价格比用灰铸铁提高几倍至十多倍。另外,生产制造水泵的厂,用不锈钢铸造时需要电炉等一套昂贵铸钢设备,多数厂家只得委托加工不锈钢铸件。且     

冷加工变形对1Cr18Ni9Ti不锈钢在含溴醋酸溶液中耐腐蚀性能的影响

在室温条件下,通过单轴拉伸试验对1Cr18Ni9Ti不锈钢产生不同程度的塑性变形,利用铁磁法测量得到了塑性变形量与α＇-马氏体相含量的关系.在此基础上,采用化学浸泡法和电化学测量技术对产生塑性变形的1Cr18Ni9Ti试样在含溴醋酸环境下的腐蚀行为进行了研究.结果表明：冷加工变形诱发马氏体相变,1Cr18Ni9Ti不锈钢的年腐蚀速率增加,点蚀电位下降,点蚀敏感性增强;但在18%～27%塑性变形量下,1Cr18Ni9Ti不锈钢耐腐蚀性能增强.     

新型高温高压汽轮机汽封片材料选用分析

针对国内新型高温高压汽轮机汽封片在高温环境下长期工作时容易出现高温蠕变、腐蚀,进而产生汽封片崩裂脱落造成汽轮机效率降低甚至出现运行事故的问题,对国内新型高温高压汽轮机汽封片选用的几种不锈钢材料从金属材料学方面进行了对比分析,并结合国际上在高温高压汽轮机汽封片材料选用方面的先进研究与应用,专门探讨了多种奥氏体不锈钢和马氏体不锈钢的材料特点,研究分析了不同不锈钢材料对新型高温高压汽轮机汽封片工作环境的适用性。研究结果表明,奥氏体不锈钢06Cr18Ni11Ti较1Cr18Ni9Ti和06Cr19Ni10更适合作为新型高温高压汽轮机汽封片选用材料,如果在条件允许的情况下,选用回火索氏体不锈钢,如X20Cr Mo13或者类似化学成份的马氏体不锈钢,作为新型高温高压汽轮机汽封片是目前最优选择。     

Corrosive Wear Behaviors of Carbon Steels in Oil-Water Fluid

Carbon steel (CS) is the most common material used in oil production. Based on surface wetting state, the corrosive wear behavior of CS in oil-water fluid was investigated. The surface wetting state of the metal in oil-water fluids with different water cut and flow velocity was measured using a specially constructed device. Wear loss, corrosion loss, and corrosive wear loss of the CS samples in different oil-water fluids were measured by a reciprocating corrosive wear tester. The damage morphology of the CS samples was observed using scanning electron microscopy (SEM) and the element distribution on the surface was detected by energy-dispersive X-ray spectroscopy (EDS). The results indicated that the surface water wetting rate of the metal increased with water cut and decreased with flow velocity in the oil-water fluid. Wear, corrosion, and corrosive wear behavior of the CS was related to the surface wetting film and surface reaction film. In this test range, the synergetic action is negative and chlorine embrittlement occurs in the fluid with high water cut and low velocity. The damage mechanism of the CS was abrasive wear with selective corrosion.     

铬-锰-氮奥氏体不锈钢在含沙海水中的冲蚀磨损行为研究

采用自制的圆筒型冲蚀磨损仪,对低、中、高流速条件下Cr-Mn-N不锈钢在含沙海水中的冲蚀磨损行为进行了研究。通过测定试样冲蚀失重率及扫描显微镜显微分析方法,研究材料在含沙清水和含沙海水中的相对耐冲蚀性和冲蚀机制。研究结果表明:试样在含沙海水中的冲蚀率均超过了在含沙清水中的冲蚀率,并随着流速的增大而增大,但增大的趋势逐渐放缓;在含沙清水中磨损机制以微切削为主,属磨料磨损;而在含沙海水中以腐蚀磨损为主,属小角度剥蚀。     

冲击形式产生的冲蚀、空蚀和腐蚀联合磨损试验研究

舰船等海洋运输装备在海水中行驶时,船体表面受到含沙海水的冲蚀磨损,舰船行驶速度变化引起的空蚀磨损,以及海水的腐蚀磨损,因此舰船表面材料的破坏形式是冲击式的冲蚀、空蚀和腐蚀联合磨损。为了研究联合磨损的影响因素,研制冲蚀、空蚀和腐蚀联合磨损试验台,并实验研究沙粒浓度、沙粒尺寸、含盐浓度以及冲蚀速度对45钢试件的联合磨损影响规律。实验结果表明:冲蚀、空蚀和腐蚀联合磨损程度强于冲蚀和空蚀交互磨损或单纯腐蚀磨损,在较低的沙粒浓度和较低的含盐浓度条件下,金属材料联合磨损质量损失与沙粒浓度、沙粒尺寸、含盐浓度和冲蚀速度均成正比关系。磨损面形貌分析表明:随着沙粒浓度、沙粒尺寸、含盐浓度、冲蚀速度的增加,试件表面的冲蚀沟和空蚀孔的磨痕深度和面积增大,而在人造海水中,试件表面不仅存在冲蚀沟和空蚀孔,还产生了腐蚀坑。     

不同环境介质下氧化铝陶瓷与耐蚀金属摩擦磨损行为

为优选海水淡化高压泵关键零部件耐磨性能材料,以Al_2O_3陶瓷与TC4钛合金、316不锈钢、2205双相不锈钢组成的配对摩擦副作为研究对象,利用立式万能摩擦磨损试验机开展干摩擦、纯水及海水3种环境介质下配对材料的摩擦磨损试验,定量得到各摩擦副摩擦因数、磨损量,并对摩擦试样的表面形貌进行分析;采用正交试验法分析载荷、转速、环境介质对摩擦因数和磨损量的影响规律。结果表明:在相同的条件下,TC4钛合金与陶瓷配副摩擦因数较小,2205双相不锈钢与陶瓷配副磨损量较小;环境介质对摩擦因数影响较大,载荷对磨损量的影响较大;海水环境下2205双相不锈钢和316不锈钢磨痕较浅,磨损机制为疲劳磨损、磨粒磨损和腐蚀磨损的交互作用。     

The slurry erosive wear of physically vapour deposited TiN and CrN coatings under controlled corrosion

The erosion-corrosion of mild steel (BS6323), in the presence and absence of physically vapour deposited (PVD) TiN and CrN coatings, was studied, in comparison with that of AISI 304 stainless steel, in an aqueous alkaline slurry solution containing alumina particles. The influence of applied potential and particle velocity on the total erosion-corrosion loss was examined, and the respective corrosion and erosion damage (both contributing to the overall weight loss) then assessed by means of microscopical investigation of the morphology of the damaged surface, and subsequently evaluated quantitatively. The superior erosion-corrosion resistance of both the coatings compared to that of the uncoated mild and stainless steels was shown to be due to their resistance to both wear and corrosion. According to the detailed corrosion mechanisms revealed and different responses to wear, schematic diagrams were proposed to outline the main features of the corrosion-erosion process and the individual roles of erosion and corrosion. Discrete differences, in terms of the respective erosion and corrosion processes, between the TiN and CrN coatings, and between the mild and stainless steels, were also investigated and discussed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Arc Erosion Wear Characteristics and Mechanisms of Pure Carbon Strip Against Copper Under Arcing Conditions

The wear behavior of pure carbon strip against copper (carbon/copper pair) under continuous arcing condition was investigated. To simulate the extreme condition of continuous arc discharge at high current, sliding wear tests were conducted on a home-made wear tester. The arc erosion wear characteristics and mechanisms of carbon/copper pair were studied by analyzing the wear scars and wear debris of the carbon strip in detail. Therefore, various analytical techniques, including Raman spectroscopy, transmission and scanning electron microscopy, and focused ion beam systems, were utilized to characterize the wear scars and wear debris of the carbon strip. The results show that the wear rate and the degree of arc erosion of the carbon strip increase with increasing electric current density. Typical entwined turbostratic carbon nanospheres (ETCNs) exhibited sphere-like stacking structure that were observed in the microstructure of the wear debris of the carbon strip produced during the friction process with current, which is the characteristic of the textural changes in carbon materials under combined arcing and sliding friction conditions. Moreover, the number and size of ETCNs increase with the electric current density increase. The arc erosion wear mechanisms of the carbon/copper pair are mainly due to the synergetic action of oxidation ablation, local electric arc impact and high-temperature graphitization under continuous arcing.     

A New Phenomenon Observed in Determining the Wear-Corrosion Synergy During a Corrosive Sliding Wear Test

Corrosive wear of materials is a complex surface failure process, which involves both the wear-accelerated corrosion and the corrosion-accelerated wear. Separating contributions of these two processes to the total material loss is of significance for gaining better understanding of the wear-corrosion synergy. Previous studies have generated an electrochemical scratch technique for measuring the wear-accelerated corrosion, based on which other components involved in the wear-corrosion synergy can be determined. In this article, a new phenomenon in measuring the wear-accelerated corrosion is reported. It was observed that for non-passivation materials there existed a stirring effect (by pin), which significantly affected the measurement. The resultant mistake was serious. The previous technique was modified accordingly and applied to determine the corrosion-wear synergy of AISI 1045 steel in comparison with that of AISI 304 stainless steel.     

Investigation of the Synergism of Wear and Corrosion Using an Electrochemical Scratch Technique

Corrosive wear of materials is a complicated surface failure process. The synergism of wear and corrosion involves both the wear-accelerated corrosion and the corrosion-accelerated mechanical failure. In this work, attempts were made to determine mass losses from these two processes using an electrochemical scratch technique. 340 stainless steel and a cast iron were studied as sample materials. For both the materials, the wear-accelerated corrosion was significantly higher than the static corrosion, due to the failure of passive film or adsorption layer. Regarding the corrosion-accelerated wear, 304 steel showed higher resistance, attributed to its passivation capability and associated protective passive film.     

Corrosive wear of carbon and austenitic stainless steels in NaCl solution

The wear rates of an AISI 52100 carbon steel and a type 316 austenitic stainless steel and the corrosion current I from the rubbing steels were measured in NaCl solution to study the interrelationship between the corrosion and wear of the steels. An on-off cyclic loading test was also conducted to examine the effect of static corrosion during an unloading period on the corrosive wear of the steels.

It was found that the wear rates of the carbon steel and the type 316 stainless steel reach a maximum at NaCl concentrations of about 3% and 0.1% respectively. The on-off cyclic test has shown that corrosive wear of the steels is influenced by static corrosion during an unloading period. The increment †I of the corrosion current due to sliding was associated with the corrosive wear rate of the steels.     

Erosion-corrosion of candidate HVOF aluminium-based marine coatings

This paper describes gravimetric results of HVOF sprayed commercially pure Al and Al/12% Si eutectic alloy coatings obtained under erosion-corrosion conditions. The performance of these coatings are compared to a hot-dipped zinc coating. These coatings have been applied to AISI 1020 carbon steel substrates and tested in a free jet impingement rig with a variety of fluids and slurries to enable the erosion and corrosion contributions to the total erosion-corrosion removal of the surface to be determined. Tests have been conducted at 30° and 90° jet impingement angles at jet velocities of 3.5 m/s.Erosion damage mechanisms are identified and the erosion-corrosion mass loss results discussed in terms of the contributions made by erosion and corrosion. Zinc was found to suffer severely from flow corrosion, while the other targets did not. All target materials under sand erosion lose mass in a way directly proportional to kinetic energy, and inversely related to hardness. Corrosion losses are relatively small while the generation of solid products sometimes results in net weight gains. There are greater mass losses at nominally normal incidence than at nominally oblique incidence, due to particle interference effects. Synergy is found to be both positive and negative and appears to be angle dependent, but is difficult to determine precisely.