腐蚀疲劳过程中裂尖阳极溶解对裂纹扩展的作用

在模拟腐蚀疲劳裂尖介质中,分别用铂丝和40CrNiMo钢为辅助电极测定了在不同拉伸速率下中温回火的40CrNiMo钢的腐蚀电流密度i_(a)与应变速率、塑性应变量的关系,其结果为:利用疲劳裂纹尖端应变的弹塑性有限元计算,得到腐蚀疲劳裂尖阳极溶解引起的裂纹扩展与△K的关系,结果表明:中温回火的40CrNiMo钢在3.5％NaCl水容液中裂尖阳极溶解对腐蚀疲劳裂纹扩展的直接贡很小,阳极溶解的主要作用是影响为裂尖断裂区氢致开裂提供氢原子的阴极过程。     

含硫钻井液中碳钢的腐蚀及腐蚀疲劳行为

通过滚轮失重,电化学极化曲线测量,氢扩散,腐蚀疲劳,扫描电镜分析,对碳钢在含硫聚合物钻井液中的腐蚀及腐蚀疲劳行为进行了研究。结果表明：硫化物的存在能减缓碳钢的均匀腐蚀,但增大其点蚀敏感性,促进碳钢中氢的扩散进入,从而加速碳钢的腐蚀疲劳破坏。     

环境对双相钢疲劳性能的影响

本文研究了自来水和3.5％NaCl水溶液分别在全浸和干湿交替状态下对热轧双相钢疲劳性能的影响.结果表明:与空气中的疲劳寿命相比,腐蚀环境有不同程度的降低作用,并以喷雾盐水影响最大.在相同腐蚀条件下,环境的影响随应力幅的降低而增强.马氏体抗疲劳断裂的能力高于铁素体.试样表面和断口的观察结果发现,腐蚀疲劳裂纹萌生与腐蚀坑密切相关,蚀坑以阳极溶解方式形成.     

CORROSION FATIGUE BEHAVIOR OF STAINLESS STEEL 3RE60 IN 3.5% SODIUM CHLORIDE SOLUTION

The corrosion fatigue behavior of stainless steel 3RE60 in 3.5%NaCl solution was studied at different cyclic stress levels. The results showed that both intergranular corrosion cracking and transgranular corrosion cracking initiated at the bottom of pits. The corrosion fatigue behavior of 3RE60 may be related to complex electrochemical and mechanical coupling effects between the three phases (austenite, ferrite and martensite), where martensite and ferrite were anodic in the corrosion cell and could be prone to crack under certain conditions.     

几种低合金钢在NaCl水溶液中腐蚀疲劳的研究

本文对几种低合金钢在3.5%NaCl 水溶液中的 CF 进行了实验研究。首先在室温下对其抗 CF性能作了比较,进而研究了温度对18Nb 钢 CF 裂纹扩展速率的影响.求出该钢在3.5%NaCl 水溶液中 CF 裂纹扩展激活能为7.4～7.9kcal/mol。认为氧的去极化反应可能是控制18Nb 钢 CF 裂纹扩展速率的主要因素。     

316L不锈钢在模拟人体液内腐蚀疲劳裂纹萌生和扩展过程中应力的作用

探讨应力在316L不锈钢腐蚀疲劳过程中的作用。应力降低了不锈钢的点蚀电位,促进了腐蚀疲劳裂纹的萌生和扩展。初始疲劳裂纹在点蚀孔中的晶界上萌生,在应力的作用下,裂纹由沿晶变为穿晶扩展,并在断口上产生二次裂纹和疲劳辉纹。     

火焰喷焊对碳钢疲劳寿命的影响

对三种不同基材状态的45~3钢经表面火焰喷焊Ni60后的疲劳性能及腐蚀疲劳性能变化的研究,表明强度高的调质态基材喷焊后的疲劳极限下降7%,而正火态和轧态基材喷焊后疲劳极限提高14%。当有3.5%NaCl腐蚀介质存在时,不管基材强度高或低,表面喷焊都使材料的腐蚀疲劳强度(10~7寿命)提高30%以上。文中通过断口金相分析阐明喷焊后基材表面组织结构变化及其对疲劳裂纹形成及扩展的影响,讨论了Ni60喷焊层在腐蚀疲劳过程的行为,为喷焊工艺在工业中的应用提供了依据。     

A NOTE ON THE CORROSION FATIGUE OF STEEL 16MnRE

<正> 本文研究温度对16MnRE钢在H_2S饱和水溶液中疲劳扩展速率的影响,是前文的继续。进一步检验以前所得的结果在不同温度下是否仍然正确;并测定腐蚀疲劳裂纹扩展的激活能,了解H_2S饱和水溶液腐蚀环境对16MnRE钢疲劳裂纹扩展影响的实质。 一、实验方法 16MARE钢热轧后,试验前未经热处理。其化学成分(wt-％)为     

奥氏体不锈钢在MgCl2介质中的应力腐蚀疲劳特征

本文研究了力学因素对0Cr18Ni9Ti奥氏体不锈钢在MgCl_2水溶液中应力腐蚀(SCC)和腐蚀疲劳(CF)交互作用的影响。研究了应力腐蚀疲劳(SCF)在裂纹扩展规律及断口形貌上的特征。结果表明:任何促使裂尖应变速率提高的力学变量,都有可能使SCF断口形貌发生穿晶型向沿晶型的转化。     

渗铝复合激光冲击对321不锈钢腐蚀疲劳性能的影响EI北大核心CSCD

针对聚焦型太阳能热发电换热管材料在熔融铝硅环境中易发生腐蚀疲劳失效的问题,采用粉末包埋渗铝和激光冲击对AISI 321不锈钢进行表面改性,研究其熔融铝硅环境下腐蚀疲劳性能。结果表明,渗铝钢表面形成以FeAl金属间化合物为主的渗层,尽管能够有效地隔离基体和腐蚀介质,但是作为疲劳裂纹的形核源,会导致腐蚀疲劳寿命降低40%;经不同功率密度的激光冲击强化处理后,渗铝钢表面硬度显著提高,延缓了疲劳裂纹萌生,提升了耐蚀性,降低了腐蚀损伤的影响,疲劳损伤占据主导地位,使得渗铝钢腐蚀疲劳寿命提高100%~200%。     

植入铸造不锈钢髋关节断裂失效事例分析

利用ＳＥＭ对实际使用时断裂的髋关节的断口和表面进行了分析，认为此关节的断裂为以弯曲应力为主的腐蚀疲劳断裂。疲劳裂纹首先在表面的腐蚀点孕育产生，应力和腐蚀的共同作用使得裂纹得以扩展断裂。     

国产Z向钢在不同腐蚀条件下的疲劳性能

本文给出了国产Z向钢在干湿交替和全浸盐水条件中的腐蚀疲劳行为,并与国外同样强度级别的A537CL1钢的腐蚀疲劳性能进行比较结果表明:它们的腐蚀疲劳性能均大致相同.本文还研究了循环频率及介质温度对腐蚀疲劳性能的影响.     

Untersuchung des SwRK-Verhaltens des martensitaushärtenden Stahls X 5 CrNiCuNb 17 4 PH im Vergleich zum weichmartensitischen Stahl X 4 CrNiMo 16 5 1 ESU in chloridhaltigen wäßrigen Medien. Teil 1: Korrosionsuntersuchungen und SpRK-Untersuchungen zur Optimierung der Wärmebehandlung bezüglich der SpRK-Beständigkeit

Investigations of the corrosion fatigue behaviour at a super pure martensitic stainless steel (X 5 CrNiCuNb 17 4 PH) in comparison to the soft martensitic stainless steel X 4 CrNiMo 16 5 1 ESR in chloride containing aqueous media — Part 1: Corrosion investigations and stress corrosion tests to optimize the heat treatment according to the stress corrosion resistance The aim of this investigation was to improve the reliability of operation and the economy of corrosion fatigue stresses of structural elements, especially at elevated temperatures, by optimizing the material. This investigation is of great interest both to the industry and to related fields. It concerns the influence of a higher degree of purity achieved by the secondary metallurgical aftertreatment of soft martensitic steel X4CrNiMo 16 5 1 ESR (ESR-electroslag remelting) in comparison to the corrosion fatigue behaviour of the precipitation hardening steel X5CrNiCuNb 17 4 PH, which was specially heat-treated with respect to stress corrosion cracking resistance. The stress corrosion was investigated for all heat-treatments of the 17-4 PH in 22% NaCl(pH3) solution. The precipitation hardening steel was most resistant to stress corrosion in concentrated NaCl-solution after a three-stage heat-treatment. There was no improvement of corrosion fatigue resistance after metallurgical aftertreatment of soft martensitic steel compared to the untreated material. This is due to the instable passive behaviour of the material which led to crack initiation, especially during the 150°C experiments, at chloride-induced places of pitting. The investigation of the electrochemical corrosion behaviour of both materials showed that the pH-value hardly influences corrosion restistance. An increase of the salt content leads to higher pitting induction. At temperatures of 80°C in a saturated NaCl-solution the material showed no corrosion resistance. In potentiokinetic investigations, a direct transition from the active area to the pitting potential was observed. In accordance with both the corrosion fatigue and the stress corrosion cracking investigations, it was found that pitting at the martensite precipitator starts primarily around Cu-containing or oxidic inclusions.     

低碳钢的组织对腐蚀疲劳的影响

本文研究了两种低碳钢不同显微组织在盐水和空气中的疲劳裂纹扩展行为,发现显微组织对钢的腐蚀疲劳抗力有重要影响。还讨论了钢的腐蚀疲劳机制及断裂机制图。     

外加电位对奥氏体不锈钢应力腐蚀与腐蚀疲劳交互作用的影响SCIEI

本文研究了0Cr18Ni9Ti奥氏体不锈钢在42%沸腾MgCl_2中,在低频,高平均应力循环载荷下的环境敏感断裂行为,研究了应力腐蚀疲劳与应力腐蚀在裂纹扩展规律及断口形貌上的差别与联系。从断裂特征上分析了应力腐蚀与腐蚀疲劳的交互作用,并着重研究了外加极化电位对这种交互作用的影响。     

CORROSION FATIGUE CRACK INITIATION BEHAVIOR OF 316L STAINLESS STEEL IN HANK’S SOLUTION

ＣＯＲＲＯＳＩＯＮＦＡＴＩＧＵＥＣＲＡＣＫＩＮＩＴＩＡＴＩＯＮＢＥＨＡＶＩＯＲＯＦ３１６ＬＳＴＡＩＮＬＥＳＳＳＴＥＥＬＩＮＨＡＮＫ’ＳＳＯＬＵＴＩＯＮ￥Ｊ．Ｈ．Ｘｉｅ;Ｙ．Ｓ．Ｗｕ;Ｊ．Ｑ．Ｈｅ;Ｘ．Ｚ．ＹａｎｇａｎｄＲ．Ｚ．Ｚｈｕ（Ｄｅｐａｒｔｍｅ...     

EFFECT OF POTENTIAL ON INTERACTION BETWEEN STRESS CORROSION CRACKING AND CORROSION FATIGUE OF AUSTENITIC STAINLESS STEEL IN BOILING 42% MgCl_2 SOLUTION

The environment-sensitive fracture behaviour of 0Cr18Ni9Ti austenitic stainless steel inboiling 42% MgCl_2 under the specific load of low frequency and high mean stress was inves-tigated from the relations and differences of crack growth rates and fractographs betweenstress corrosion fatigue and stress corrosion cracking.The interaction between stress corro-sion cracking and corrosion fatigue was also studied from fracture characteristics with empha-sis on the effects of applied potential on the interaction.     

Versprödungserscheinungen an ferritischen Chromstählen und deren Einfluß auf das Schwingungsrißkorrosionsverhalten

Embrittlement conditions of ferritic chromium steels and influence on the corrosion fatigue behaviour The corrosion fatigue behavior of two ferritic stainless steels, with 18% and 28% chromium respectively, embrittled by α'- or sigma-phase has been studied in this investigation. No effect of the α'-phase on the corrosion fatigue behaviour in a 0.5 N or 4 N air saturated soldium chloride solution at 80 °C has been found. In the 4 N solution corrosion fatigue cracking of the 18% chromium steel in the solutionized as well as in the α'-embrittled condition is initiated by pitting at nonmetallic inclusions. Sigma-phase not only decreases the mechanical properties of the 28% chromium steel by heavy embrittlement but also leads to crack initiation by pitting in the 4 N solution at the interface sigma/ferrite. The pronounced decrease of the corrosion fatigue properties of the 28% chromium steel could well be correlated with chromium depletion of the ferrite matrix by precipitation of sigma phase.     

Vergleichende Untersuchungen des SwRK-Verhaltens verschiedener Dampfturbinenschaufelstähle

Comparative investigations into the corrosion fatigue behaviour of different steam-turbine-blade steels Corrosion fatigue tests in NaCl-solution in the temperature range from ambient temperature to 150°C revealed a decrease of the corrosion fatigue strength of the steels X20Cr13 with 1% resp. 2.5% Mo, X4CrNiMo 16 5 1 and X2CrNiMoN 22 5 with increasing temperature; a minimum of the corrosion fatigue strength is reached at 150°C. At temperatures of about 80°C it was found an optimum corrosion fatigue behaviour of the Mo-alloyed steel X20CrMo13 2.5 in comparison with the other investigated steels. It was observed that crack initiation of the ferritic, Mo-alloyed steel is caused by Cl-induced pitting, of the soft martensitic steel by oxide inclusions and of the duplex steel by non metallic, brittle inclusions and/or by grain boundarys of the ferritic/austenitic microstructure. Crack initiation caused by pre-deformation at slip bands was observed on the duplex steel. All materials investigated failed at elevated temperatures. At temperatures higher than 80°C an optimum corrosion fatigue behaviour was not found.     

气相环境阴极保护对耐候钢腐蚀疲劳行为的影响

<正> 电化学保护能否在气相环境中使用是人们一直希望解决的问题。一九八八年研究出了气相环境中的阴极保护方法,用于架空金属管道、桥梁、铁轨及海洋工程构件的飞溅区保护,并在架空金属管道的实际试验中取得了良好的保护效果,其保护原理见文献。本工作探索气相