含Cu抗菌不锈钢的工艺与耐蚀性能

与普通0Cr17铁素体不锈钢和0Cr18Ni9奥氏体不锈钢相比，含铜铁素体和奥氏体抗菌不锈钢均具有良好的冷热加工性能和焊接性能．通过提高浇铸温度，抗菌不锈钢能保持良好的铸造性能．奥氏体抗菌不锈钢的抗应力腐蚀性能比0Cr18Ni9不锈钢有很大的提高，而铁素体抗菌不锈钢比0Cr17有明显的下降．与相应的普通不锈钢相比，两种类型抗菌不锈钢的耐点蚀性能均略有下降．     

奥氏体抗菌不锈钢的微观组织及抗菌性能

含Cu奥氏体抗菌不锈钢经特殊的抗菌热处理析出ε—Cu相,采用覆膜法研究其抗菌性能。实验结果表明：奥氏体抗菌不锈钢易于杀灭大肠杆菌和金黄色葡萄球菌;杀灭鼠伤寒杆菌需要一定时间;杀灭白色念株菌需要较长时间。这与细菌的细胞壁组织结构、细胞壁厚度及其属性有关。抗菌不锈钢对细胞壁较薄、肽聚糖含量较低、组织疏松、金属离子易穿透细胞壁的细菌易于杀灭;反之,细菌不易于杀灭。随着抗菌作用时间的延长,溶液中铜离子浓度的提高,抗菌不锈钢的杀菌效力显著提高。奥氏体抗菌不锈钢经表面打磨或磨损仍然具有同样的抗菌性能。     

铜对低碳马氏体抗菌不锈钢性能的影响

在低碳马氏体不锈钢中添加适量Cu,经过抗菌热处理,使不锈钢具有优良的抗菌特性。利用X射线衍射仪和恒电位仪分析了抗菌处理后相的分布和耐蚀性,并通过覆膜法测定其抗菌性。结果表明,随着Cu含量的增加,含铜马氏体不锈钢的硬度和抗菌性提高,维钝电流密度、致钝电流密度和致钝电压减小,更易于钝化。     

含铜铁素体抗菌不锈钢的杀菌机理的初步研究

通过杀菌性能、蛋白质溶出、添加半胱氨酸等实验，并利用生物透射电镜技术，对含铜铁素体抗菌不锈钢对大肠杆菌的杀灭作用机理进行了初步研究。结果表明抗菌不锈钢对大肠杆菌的杀菌率达到99．99％。进一步的研究发现，大肠杆菌与抗菌不锈钢作用后，其细胞壁和细胞膜破裂，细胞膜脂质和含-SH等还原基团酶发生氧化，细胞内出现了明显的内含物溢出现象。随着与抗菌不锈钢作用时间的延长，细菌细胞内的蛋白质漏出量不断增加，最终致使细菌死亡。     

含Cu铁素体抗菌不锈钢的抗菌性能

含Cu铁素体抗菌不锈钢在抗菌热处理过程中析出ε-Cu相,具有抗菌功能.抗菌处理的条件影响析出相的数量和形貌,从而影响其抗菌特性.在时效温度较低时,抗菌析出相基本上呈球形,随着时效温度的升高,析出相逐渐变为长条形并与铁素体基体保持某种取向关系.在抗菌不锈钢抗菌过程的前期,抗菌性能表现为对细菌生长和繁殖的抑制,后期表现为对细菌的杀灭.     

时效处理对含铜马氏体抗菌不锈钢抗菌性能的影响

利用覆膜法研究了时效温度和时效时间对含铜马氏体不锈钢抗菌性能的影响，结果表明当不锈钢经过500℃时效处理时就表现出明显的抗菌性能；当时效温度升高至700℃时不锈钢对大肠杆菌和金黄色葡萄球菌的杀菌率达到99．9％以上，表现出优秀的抗菌性能。     

钨含量对新型高铬锰氮双相不锈钢Cr29Mn12Ni2N0.6Wx组织和性能的影响

研究了钨含量对新型高铬锰氮双相不锈钢Cr29Mn12Ni2N0.6Wx(x=1,2,3)显微组织、力学性能和耐腐蚀性能的影响。结果表明:Cr29Mn12Ni2N0.6Wx不锈钢固溶处理后具有典型的铁素体+奥氏体双相组织,铁素体含量在45%~60%范围内;随着钨含量的增加,合金中σ相的析出倾向增强,铁素体含量增加,合金的耐腐蚀性能降低,屈服强度和抗拉强度升高;经1 050℃固溶处理30 min后,该系列双相不锈钢中不再有σ相析出,其屈服强度大于650 MPa,抗拉强度大于900 MPa,断后伸长率大于30%,作为高强度资源节约型超级双相不锈钢具有潜在应用前景。     

不锈钢表面含银有机硅烷偶联剂抗菌耐蚀薄膜制备和性能

通过溶胶-凝胶方法在乙烯基三甲氧基硅烷偶联剂中加入银离子,得到含银有机硅烷水解溶液,在不锈钢表面制备了抗菌、耐蚀的不锈钢抗菌膜层,研究了银离子的掺入工艺以及薄膜的抗菌性能和耐蚀性能.抗菌性能研究结果表明:银离子含量增加到3%以上时,样品的抗菌性能均增加到99.9%以上.样品经过24h去离子水的浸泡后,所有样品的抗菌性能均有所降低;银离子含量越高的样品抗菌性能保持得越好,不锈钢表面经过预氧化处理的略优于表面未经预氧化处理的薄膜.10?Cl3溶液点蚀实验测试结果表明,样品的耐腐蚀性能有明显提高,点蚀率仅为相同条件下不锈钢的1/40.     

含铜抗菌不锈钢拉伸过程中的微观组织演变EBSD分析

目的 研究含铜抗菌不锈钢拉伸性能,为工业生产中的成形工艺优化提供一定的理论依据。方法 在拉伸应变分别为5%、15%、30%、45%、60%、75%以及最后拉伸断裂时应变为81%条件下,采用岛津AGS-100KN万能拉伸试验机对含铜抗菌不锈钢进行拉伸试验。通过扫描电子显微镜(SEM)、电子背散射衍射仪(EBSD)和透射电子显微镜(TEM)表征分析含铜抗菌不锈钢拉伸断裂后的断口形貌以及拉伸过程中的微观组织演变。结果 含铜抗菌不锈钢抗拉强度最大值为587.523 MPa,应变最大值为81%。拉伸断口与拉伸方向呈45°开裂,呈杯锥状,断裂模式是韧性断裂。结论 随着应变的增大,低角度晶界逐渐增多,高角度晶界与孪晶逐渐减少,GOS值逐渐增大,Goss织构、S织构和R织构含量逐渐减少,Brass织构含量逐渐增加,拉伸断裂后的体积分数为23.3%。在拉伸后期,Copper织构和Brass织构含量较多,在拉伸过程中起到整体稳定协调微观组织作用的S织构不断减少,随应变的增大,组织内部协调变形加快,变形程度快速增大,从而导致S织构向Copper织构和Brass织构转变,出现板条状马氏体,存在应变诱发马氏体相变。位错滑移、形变孪晶和形变诱导马氏体等多种变形机制的共同作用使含铜抗菌不锈钢具有良好的塑性。     

含铜奥氏体抗菌不锈钢抗菌性能和机理初步研究

考察了含铜奥氏体抗菌不锈钢的抗菌性能，并对其抗菌机理进行了初步探讨。方法：覆膜法测定杀菌率；透射电镜观察E．coli细胞形态；考马斯亮蓝法测定细胞漏出液中可溶性蛋白含量；琼脂糖凝胶电泳检测菌体基因组DNA考察抗菌不锈钢对DNA的剪切作用。结果：除产气肠杆菌外，奥氏体抗菌不锈钢对其它供试的16种常见微生物均显示较强的抗菌活性，具有广谱抗菌性．在作用9h时可将1×10^7cfu／ml的E．coli全部杀灭，对浓度≤1×10^7cfu／ml的E．coli液在24h内杀灭率达到99．5％。透射电镜结果显示，与奥氏体抗菌不锈钢作用后的E．coli细胞壁和细胞膜破裂，核区不明显；作用后的菌液中可溶性蛋白质含量增加；实验中未检测到有明显的菌体DNA断裂现象．结论：奥氏体抗菌不锈钢具较强的抗菌性能和广谱抗菌性。其作用机理可能为使菌体细胞壁和细胞膜因氧化而破裂，胞内可溶性蛋白漏出，最终导致菌死亡。     

高强马氏体不锈钢板材厚度方向组织与性能

采用金相显微镜、扫描电镜及能谱仪显微分析和力学性能测试等方法研究了高强马氏体不锈钢板的析出相－铁素体的形貌、成分及其板厚方向性能与横向性能的差别。结果表明，０Ｃｒ１６Ｎｉ５Ｍｏ钢在轧板之后形成的沿轧制方向的铁素体层严重影响板厚方向的塑性，但通过适当的热处理可以改变这种层状铁素体结构，进而大幅度改善板厚方向的塑性。     

不锈钢表面渗铜扩散复合处理合金层的抗菌性能研究

采用等离子表面合金化及辉光轰击热扩散复合处理技术在不锈钢表面进行了铜合金化处理. 利用薄膜密贴法对改性层的抗菌性能进行了测试. 通过扫描电子显微镜(SEM)、辉光放电光谱分析仪(GDOES)和X射线光电子能谱(XPS)等手段, 研究了铜合金层的微观组织、化学成分分布及抗菌前后表面铜的价态变化. 结果表明, 铜合金层对大肠杆菌(E. coli)和金黄色葡萄球菌(S. aureus)都展现了优良抗菌性能; 合金层表面铜约为5.7wt%, 合金层厚度约2.7 µm; 表面铜合金化不锈钢与菌液接触后, 不锈钢表面的铜元素以铜离子析出, 并且与试验菌种发生作用, 杀灭试验细菌.     

Influence of grain refining elements on mechanical properties of AISI 430 ferritic stainless steel weldments – Taguchi approach

The effect of grain refining elements such as copper, titanium and aluminum on transverse tensile strength, ductility, impact toughness, microhardness and austenite content of AISI 430 ferritic stainless steel welds through Gas Tungsten Arc Welding (GTAW) process in as-welded condition was studied. Taguchi method was used to optimize the weight percentage of copper, titanium and aluminum for maximizing the mechanical properties and austenite content in the weld region of ferritic stainless steel welds. Based on Taguchi orthogonal array the regression equations were developed for predicting the mechanical properties of ferritic stainless steel welds within the range of grain refining elements. The observed mechanical properties and austenite content have been correlated with microstructure and fracture features.     

热处理温度对海水循环泵叶轮用双相不锈钢冲击性能的影响

针对海水循环泵叶轮的服役条件,利用烟台台海玛努尔核电设备有限公司提供的材料,研究了热处理工艺对GX2GrNiMoN22-5-3双相不锈钢冲击性能的影响。结果表明,双相不锈钢的冲击性能在常温下随固溶温度的升高而逐渐下降,并且在1120～1160℃固溶温度范围内下降明显,在1160～1200℃温度范围内下降趋势缓慢。铁素体含量测试表明,随固溶温度的升高,铁素体的变化趋势与冲击功的变化趋势具有良好一致性,表明固溶温度升高铁素体含量降低,是冲击功减小的重要原因。对冲击断口形貌进行观察,冲击断口以韧窝型断裂为主。     

Cold roll bonding of bimetallic sheets and strips

Abstract

The successful production of wide bimetallic sheets and strips by cold roll cladding depends on the technical solution of reduction of rolling load while still guaranteeing good bond quality. In the present paper, systematic experimental data on the cold roll cladding of aluminium–stainless steel, copper–stainless steel, and mild steel–stainless steel are correlated and the basic mechanism is discussed, aided by a scanning electron microscopy study of the separated interface. The effects of conventional rolling and cross-shear rolling (i.e. between rolls of differing peripheral speeds) on roll force and bonding strength are critically compared. It is found that use of the cross-shear cold rolling technique results in a significant reduction in rolling load for equal primary bonding strength and that the incorporation of an optimum final heat treatment considerably decreases the requirement on rolling.

MST/971     

基于磁性测定法研究奥氏体不锈钢波纹管的形变马氏体含量

根据形变诱发马氏体磁性的变化,针对SUS304和SUS316L奥氏体不锈钢分步机械胀压成型波纹管以及未经固溶处理与经固溶处理SUS304奥氏体不锈钢液压成型波纹管,采用MP30E—S型铁素体测定仪定量测定了波纹管母材区及焊缝区的形变马氏体含量。结果表明：形变马氏体含量的大小与波纹管材料、相对变形量以及热处理状态等均有很大关系;在相同变形量条件下SUS316L不锈钢的形变马氏体含量比SUS304不锈钢要小得多;相对变形量越大,形变马氏体含量也越大,且波峰处的形变马氏体含量较波谷处的要大得多;与未固溶处理波纹管相比,经固溶处理后波纹管的形变马氏体含量显著减小。     

The electrochemical behaviour of direct strip casting stainless steel in acid solutions

The electrochemical behaviour of direct strip casting (DSC) 304 stainless steel in 0.1 M H2SO4 and 0.01M HCl solutions was investigated. The DSC 304 stainless steel strips were produced by using either copper-alloy roller or 304 stainless steel roller. The difference in thermal conductivity of different roller materials resulted in a change in the surface microstructure of the DSC strips. Potentiodynamic polarization curves of the DSC 304 stainless steels produced were measured in 0.1M H2SO4 and 0.01M HCl solutions. The results showed that both alloys could passivate in the above solutions. In the HCl solution, the passive potential range of DSC 304 stainless steel with a higher ferrite content prepared by the copper roller was wider than that with a lower ferrite content. Furthermore, the addition of silicon could cause an expansion while the addition of titanium could lead to a shrinkage in the passive range in 0.01M HCl solution. Potential decay tests in 0.1M H2SO4 solutions showed that the reactivation time decreased as the ferrite content was increased. © 1998 Chapman & Hall     

Ag/Cu共渗不锈钢表面的微观结构及抗菌性能研究

以银铜合金为靶材,利用辉光等离子体在AISI304不锈钢表面同时渗入银和铜,制备性能优良的抗菌不锈钢。对渗层的形貌、化学组成、耐蚀性能和抗菌性能进行了研究,结果表明,所得渗层在不锈钢表面分布均匀,Ag/Cu元素质量比为4.9∶3;不锈钢表面渗层腐蚀电位由-0.103V提高到0.07V,自腐蚀电流密度从1.66×10-7A/cm2降至5.813×10-9A/cm2,耐腐蚀性能有所提高;渗层对大肠杆菌和金黄色葡萄球菌的杀菌率均达100%。     

Effects of Nitrogen Concentration on Microstructure and Antibacterial Property of Copper-Bearing Austenite Stainless Steels

Austenite antibacterial stainless steels have been found to have wide applications in hospitals and food industries. In recent years epsilon copper precipitation in antibacterial stainless steels has obtained much research interest due to its antibacterial action. The objective of this study was to determine the effects of nitrogen concentration on the precipitation of epsilon copper and antibacterial property. Two kinds of austenite antibacterial stainless steels containing copper and different nitrogen concentration （0.02 and 0.08 wt pct, respectively） were prepared and the microstructures were characterized by a combination of electron microscopy and thermodynamic analysis. A mathematical expression was deduced to predict the effect of nitrogen concentration on the activity coefficient of copper, In（fCu/f^0cu）=0.53524＋4.11xN-0.48x^2N. Higher nitrogen was found to increase the free energy difference of copper concentration distribution between precipitation phase and austenite matrix, stimulate the aggregation of copper atoms from austenite, increase the precipitation amount and consequently enhance the antibacterial property of steel.