抗菌处理对含Cu奥氏体抗菌不锈钢组织和性能的影响

研究了含Cu奥氏体抗菌不锈钢的两种抗菌处理方法对其组织、抗菌性能、机械性能和耐腐蚀性能的影响。结果表明:不同的抗菌处理影响了抗菌不锈钢基体中富Cu相的析出,低温长时间抗菌处理得到的组织中富Cu相比高温短时间抗菌处理得到的富Cu相更细密,细密的富Cu相对大肠杆菌和金黄色葡萄球菌的抗菌性更好。与304不锈钢相比,含Cu奥氏体抗菌不锈钢经抗菌处理后对机械性能没有产生明显的影响,耐腐蚀性也没有明显的下降。     

整体系抗菌不锈钢材料及其制造技术

整体系抗菌不锈钢按组织分为铁素体钢、马氏体钢和奥氏体钢。铁素体抗菌不锈钢的抗菌成分有Cu、Ag；马氏体抗菌不锈钢的抗菌成分为Cu；奥氏体抗菌不锈钢的抗菌成分有Cu、Ag、V、AgO、Ag2S、Cu—Ag—Zn中间合金、银铜配合、Ce。分析了存在的问题，并提出了建议。     

含铜抗菌不锈钢的抗菌特性研究

研究了铁素体和奥氏体含铜抗菌不锈钢的抗菌特性及相关机制.实验结果表明,含铜抗菌不锈钢具有优良的广谱杀菌作用,对本文选择的大部分革兰氏阴性菌(G-)和革兰氏阳性菌(G )的杀灭率均在99.0%以上.通过铁素体抗菌不锈钢对大肠杆菌作用不同时间的研究证明,抗菌不锈钢的杀菌率和其与细菌作用时间有关,铁素体抗菌不锈钢与大肠杆菌作用150 min左右时间后的杀菌率才会达到99.9%的最大值.原子力显微镜的观察表明,抗菌不锈钢对大肠杆菌的杀灭表现为菌体内大量物质流失,细菌出现干瘪现象.电化学实验结果表明,抗菌不锈钢与大肠杆菌作用后,会由于其表面抗菌相中铜离子溶出的加快,而表现为其耐点蚀电位的下降.     

金属离子型抗菌不锈钢组织及其抗菌性能的研究

分析了高铜马氏体不锈钢和加银奥氏体不锈钢的组织及抗菌性能。通过HREM分析显示,高铜马氏体不锈钢经抗菌热处理后(600℃时效0.5 h),基体弥散分布着大量小于40 nm的球状-εCu相,与基体存在共格关系。随时效时间增长,-εCu相逐渐脱溶成为独立的富铜相。SEM分析显示加Ag奥氏体不锈钢固溶后富Ag质点分布在晶界。等离子质谱法显示表面涂覆液膜24 h后Cu2 、Ag 抗菌离子析出浓度分别达到75×10-4%和0.15×10-4%,这是高铜和加银不锈钢具有100%抗菌率的原因。     

铁素体抗菌不锈钢的抗菌特性

含Cu铁素体抗菌不锈钢的抗菌特性来自抗菌热处理过程中形成的析出相ε-Cu,抗菌处理后的抗菌不锈钢具有良好的长效广谱抗菌功能,而且对人体是安全的。抗菌功能不会因表面磨损或长期浸泡而丧失。抗菌过程可以分为两个阶段,抗菌作用主要通过与细菌的直接接触实现。     

再结晶退火温度对含Cu铁素体抗菌不锈钢耐蚀性的影响

通过金相分析、FeCl₃点腐蚀试验、点蚀坑形貌观测、极化曲线测试等方法,研究了再结晶退火温度对含Cu铁素体抗菌不锈钢耐蚀性的影响。结果表明:在860～980 ℃范围内保温5 min,含Cu铁素体抗菌不锈钢再结晶程度逐渐提升,耐蚀性先增强后减弱,最佳再结晶退火温度为900 ℃。含Cu铁素体抗菌不锈钢在酸性FeCl₃溶液中点蚀坑呈开放式,随再结晶退火温度的升高,点蚀坑面积及深度减小,在980 ℃退火时其数量明显增多。     

抗菌时效处理对含Cu双相不锈钢组织和性能的影响 Ⅱ.耐蚀及抗菌性能

采用电化学方法分析了经抗菌时效处理后的含Cu双相不锈钢耐腐蚀性能,同时采用覆膜法测试了其广谱抗菌效果.极化曲线测试结果表明,材料表面存在的ε-Cu等富Cu相成为钝化膜中的薄弱点,粗大富Cu相的时效析出位置易成为点蚀形核源,析出粗大富Cu相所占比例增加使得材料耐点蚀性能减弱;阻抗谱测试显示钝化膜中存在的ε-Cu等富Cu相会降低整体电位及钝化膜电阻,使钝化膜稳定性下降;DL-EPR测试表明,在相界及晶间析出的ε-Cu等富Cu相会使晶间呈现阳极性,导致晶间发生选择性腐蚀,因富Cu相主要在铁素体上析出,与奥氏体相比,其耐晶间腐蚀性能下降严重.抗菌检测表明,富Cu相的相结构和体积分数是影响材料抗菌性能的关键因素,ε-Cu的抗菌效果最好,亚稳态富Cu相次之,固溶Cu最差.ε-Cu相数量越多,抗菌效果越好.     

1Cr13Cu1.5马氏体不锈钢的微观组织和性能

研究了1Cr13Cu1．5马氏体不锈钢的微观组织、耐蚀性和抗菌性。扫描电镜和X-射线分析表明,1Cr13Cu1．5马氏体不锈钢经1100℃固溶处理600℃ 5h时效后,钢的基体中分布具有抗菌作用的ε-Cu相,该相对大肠杆菌的抗菌率大于95％,但该相对耐蚀性有一定的影响,使不锈钢的耐蚀略微下降。     

抗菌热处理对SUSXM7含Cu不锈钢冷加工性能的影响

研究了抗菌热处理前后SUSXM7含Cu奥氏体不锈钢的力学性能,并与通用奥氏体不锈钢SUS304进行了对比.结果表明:SUSXM7含铜不锈钢的加工硬化指数低于SUS304不锈钢,塑性应变比高于SUS304不锈钢,两种材料的杯突深度基本接近,SUSXM7含铜不锈钢的冷加工成形性能优于SUS304不锈钢.抗菌热处理后,SUSXM7含铜不锈钢的加工硬化指数、塑性应变比、杯突深度没有太大变化,抗菌热处理对SUSXM7含铜不锈钢的冷加工成形性能没有太大影响.SUSXM7含铜不锈钢可以在抗菌热处理前进行冷加工成形,也可以在抗菌热处理后再进行冷加工成形.     

不锈钢钢种发展的一些动向

从奥氏体不锈钢的演变,以氮代碳的含氮不锈钢,Mn-N系不锈钢,超级铁素体不锈钢,超级奥氏体不锈钢,超级马氏体不锈钢及抗菌不锈钢等方面的发展,概述了不锈钢钢种发展的一些动向。     

抗菌金属材料的研究进展

简要介绍了无机抗菌材料的种类和抗菌机理，综述了 抗菌金属材料的发展现状和抗菌化工艺，详细介绍了各类抗菌金属材料的特点和应用情况.并对抗菌金属材料的研究趋势进行了展望.      

EFFECTS OF COPPER ION IMPLANTATION ON ANTIBACTERIAL ACTIVITY OF AISI420 STAINLESS STEEL

1.IntroductionStainlesssteel(SS)isoften used in kitchenw ares,m edicalapparatusand facilitiesoffood process-ing. The existing and breeding ofm icroorganism on the surfaceofSS productsdo notm eethealth crite-ria and m ay do harm to people'shealth.W ith the…     

节约型双相不锈钢2101高温变形过程中微观组织演化

采用电子背散射衍射技术(EBSD)和TEM研究了节约型双相不锈钢2101在温度为1000℃和应变速率为5 s~(-1)的高温变形过程中的微观组织演化.结果表明,铁素体和奥氏体都发生以小角度晶界不断向大角度晶界转变为特征的连续动态再结晶(CDRX).固溶退火后双相不锈钢奥氏体内出现大量退火孪晶.随变形量增加,奥氏体中具有∑3位向关系的晶界逐渐消失.高温变形过程中双相微观组织演化机制的耦合作用共同决定了流变曲线特征.     

Phase Transformations of an Fe-0.85 C-17.9 Mn-7.1 Al Austenitic Steel After Quenching and Annealing

Low-density Mn-Al steels could potentially be substitutes for commercial Ni-Cr stainless steels. However, the development of the Mn-Al stainless steels requires knowledge of the phase transformations that occur during the steel making processes. Phase transformations of an Fe-0.85 C-17.9 Mn-7.1 Al (wt.%) austenitic steel, which include spinodal decomposition, precipitation transformations, and cellular transformations, have been studied after quenching and annealing. The results show that spinodal decomposition occurs prior to the precipitation transformation in the steel after quenching and annealing at temperatures below 1023 K and that coherent fine particles of L1₂-type carbide precipitate homogeneously in the austenite. The cellular transformation occurs during the transformation of high-temperature austenite into lamellae of austenite, ferrite, and kappa carbide at temperatures below 1048 K. During annealing at temperatures below 923 K, the austenite decomposes into lamellar austenite, ferrite, κ-carbide, and M₂₃C₆ carbide grains for another cellular transformation. Last, when annealing at temperatures below 873 K, lamellae of ferrite and κ-carbide appear in the austenite.     

Effect of Ni and Mn on the Mechanical Properties of 22Cr Microduplex Stainless Steel

The tensile properties of 22Cr–2Ni–4Mn–0.2N micro-duplex stainless steels with different Ni and Mn contents were investigated. Duplex stainless steels were vacuum induction melted and hot rolled, then annealed at 1,000–1,100 °C, at which temperature both the austenite and ferrite phases were stable. The volume fraction of the ferrite phase was markedly affected by the alloying elements of Mn and Ni; 1 wt% of Mn was equivalent to 0.4 wt% of Ni. All of the steels tested at room temperature showed the common strain-hardening behavior, while the steels tested at lower temperatures(-30 or-50 °C)showed a distinct inflection point in their stress–strain curves, which resulted from the transformation of the austenite to straininduced martensite. The onset strain(e0) of the inflection point in the stress–strain curve depended on the Md30 value of the steel. Testing at lower temperatures resulted in smaller e0 and consequently higher strengths and fracture strains(ef). The tensile behavior was examined from the perspective of austenite stability of the micro-duplex stainless steels with the different Ni and Mn contents.     

Effect of nitrogen on corrosion behavior of 28Cr-7Ni duplex and microduplex stainless steels in air-saturated 3.5 wt% NaCl solution

The corrosion behavior of 28Cr-7Ni-O-0.34N duplex stainless steels in air-saturated 3.5-wt% NaCl solution at pH 2, 7, 10 and 27 °C was studied by the potentiodynamic method. Two types of microstructures were investigated: the as-forged duplex and microduplex (average austenite grain size 5-16 μm) structures. The austenite volume fractions of the tested steels were between 0.35 and 0.64. The nitrogen effect on corrosion behaviors of both duplex and microduplex stainless steels were the same. At pH 2, the corrosion potential increased when the nitrogen content increased, however, corrosion current density as well as corrosion rate decreased. At pH 7 and 10, the effect of nitrogen on corrosion potential and corrosion rate could not be observed. Corrosion potential at pH 10 was lower than at pH 7. Pitting potential increased when the nitrogen content in the tested steels increased at all tested pH. For the nitrogen effect on the passive current density, it seemed that only at pH 2, the average passive current densities reduced when the nitrogen content increased. Nitrogen may have participated in the passive film or has been involved in the reaction to build up passive film. The ammonium formation and nitrogen enrichment at the interface metal/passive film with adsorption mechanism were discussed. The dissolute nitrogen might have combined with the hydrogen ions in solution to form ammonium ions, resulting in increasing solution pH. The steel could then easily repassivate, hence the corrosion potential and pitting potential would increase. However, the ammonium formation mechanism could not explain the decrease of corrosion potential in basic solution. Nitrogen enrichment at the metal/passive film interface with adsorption mechanism seemed to be an applicable consideration in increasing pitting potential. However, this mechanism did not involve the ammonium ion formation. In general, for the duplex and microduplex stainless steels tested, nitrogen increased the general corrosion resistances in acid solution and pitting corrosion resistance at all solution pH. Metallographic observation in both tested duplex and microduplex steels after pitting corrosion at all tested pH revealed that, the corroded structure in the tested steels without nitrogen alloying was austenite, but those with nitrogen alloying was ferrite. Even though ferrite had a higher chromium content than austenite but higher dissolved nitrogen in austenite than in ferrite may have increased the pitting resistance equivalent number (PRE) of austenite to be higher than that of ferrite.     

450℃渗氮AISI 316L不锈钢中膨胀奥氏体的分解

奥氏体不锈钢等离子渗氮时会形成膨胀奥氏体(γN),其强度、韧性和耐蚀性均高于传统的氮化物层。然而,膨胀奥氏体在热力学上是亚稳的,其性能会因其发生分解而降低。本文对AISI 316L不锈钢进行了等离子渗氮,工艺为450℃×5 h,压力500 Pa。对渗氮后试样采用XRD、OM和TEM等进行了显微组织表征。试验结果证明了面心立方膨胀奥氏体的存在,其晶格常数比未经渗氮奥氏体增加多达9.5%。薄片试样的TEM分析表明,N层中有细小的氮化物形成,并且发现一些区域呈奇特的层片状形貌,与碳钢中的珠光体团很相似。选区电子衍射(SAED)分析表明,这些区域由膨胀奥氏体局部分解产生的体心立方铁素体和立方晶系氮化铬组成。在所研究试样中的某些区域,发现有非晶态膨胀奥氏体。N的分解与膨胀奥氏体层局部区域中铁素体稳定元素(Cr,Mo)的显微偏析和奥氏体稳定元素(Ni)的贫化有关。