氮含量和环境温度对316L不锈钢耐腐蚀性的影响

研究低温条件下腐蚀溶液温度以及钢中氮含量对316L奥氏体不锈钢耐腐蚀性能的影响,在1mol／L H2SO4＋0．5mol／L NaCl的腐蚀液中,对氮含量为0．0095％～0．5575％的316L奥氏体不锈钢进行阳极极化曲线及电化学阻抗测量。结果表明,提高氮含量,316L奥氏体不锈钢耐蚀性增强;腐蚀液温度升高,316L奥氏体不锈钢耐蚀性减弱。     

316L不锈钢的高压增氮与脱氧研究

采用真空/高压感应炉在0.1~1.0 MPa高纯氮气氛下熔炼316L不锈钢,分析了氮的溶解度与氮分压之间的关系。氮在316L不锈钢中的溶解服从Sievert定律。采用热力学数据预测了不同氮分压下316L不锈钢中氮的溶解度,计算结果表明,预测值与实验值相吻合。采用铝、硅钙以及二者混合进行脱氧,总氧含量可以达到20×10-4%以下,提出了制备低氧高氮316L不锈钢的实验条件。     

HIPIB辐照处理对316L不锈钢耐磨性的改善

利用强流脉冲离子束（HIPIB）对316L不锈钢进行了表面辐照处理，研究了HIPIB辐照对316L表面摩擦磨损性能的影响。实验结果表明，HIPIB辐照处理后，在深度达50μm以上范围内316L的显微硬度提高，表面滑动摩擦系数降低，耐磨性得到显著改善。采用扫描电子显微镜（SEM）观察辐照前后试样的表面形貌；用X射线衍射（XRD）分析辐照前后试样表面层相结构的变化。结果发现，HIPIB辐照使试样表面光滑化，且表面层产生择优取向。HIPIB辐照引起的强大应力和冲击波使材料发生了明显的塑性变形，不仅导致“形变织构”出现，并且产生大量的位错等缺陷，形成稳定的网络分布，从而强化了316L不锈钢表面层。     

焊接工艺对316 J1L 不锈钢焊缝耐海水腐蚀性能的影响

通过提高焊接速度,减小焊接电流等手段改进316J1L的焊接工艺,提高了焊缝的耐海水腐蚀性能。利用金相显微镜、扫描电镜及X射线衍射技术对原失效焊件及改进工艺焊件三区的微观组织形貌、元素分布、物相组成等进行测定,测量2种工艺下焊件三区的动电位极化曲线,并对电化学特性进行了比较分析。结果表明:改进工艺后焊件三区平均晶粒度较大,元素分布更加均匀,腐蚀电流密度更小,腐蚀电位更高,腐蚀速率显著降低。     

ZrO2/316L不锈钢复合材料的SEM分析

采用热压（ＨＰ）烧结法制备了ＺｒＯ２／３１６Ｌ不锈钢复合材料．利用三点弯曲、单边切口梁(ＳＥＮＢ）等方法测定了材料的力学性能．通过扫描电镜(ＳＥＭ）现察复合材料的显微组织结构，研究 分析了材料在静载荷下的断裂机理．     

SLM工艺参数对316L不锈钢试件拉伸性能的影响

采用选择性激光熔化成型技术对316L不锈钢粉末进行工艺参数优化实验,以期获得拉伸性能优良的316L成型件。利用单因素实验法和正交试验探究激光功率、扫描速度和扫描间距等工艺参数对316L不锈钢成型试件拉伸性能(抗拉强度和延伸率)的影响,确定最优工艺参数水平组合。研究结果表明:激光功率对316L不锈钢成型件抗拉强度和延伸率均有显著影响,扫描速度和扫描间距的影响次之;在实验条件下,成型件拉伸性能最优工艺参数水平组合为:激光功率220 W、扫描速度960 mm/s、扫描间距0.14 mm。     

选区激光熔化制备Mo颗粒增强316L不锈钢成形工艺及组织性能研究

基于选区激光熔化(SLM)工艺,以高熔点、低激光吸收率的金属Mo颗粒为增强体成功制备出金属-金属基颗粒增强不锈钢材料。当激光功率为230 W、扫描速度为730 mm/s时,此时成形的Mo/316L不锈钢复合材料致密度最高,并可观察到大量球形Mo颗粒均匀分布于金属基体中。熔池中悬浮Mo颗粒的存在一方面加大了熔体冷却速度、过冷度和形核率,另一方面部分Mo元素融入316L金属基体中导致了铬当量Cr_eq值的增大和Ni_eq值的减小。当Mo颗粒加入量为2wt.%时,金属基体保持奥氏体相为主,晶粒明显细化和等轴化。抗拉强度提升10.77%的同时,断裂延伸率基本保持不变;当Mo颗粒加入量为6wt.%时,金属基体则从纯奥氏体结构转变为以铁素体为主的铁素体-奥氏体双相结构,材料屈服强度进一步提升46.5%,断裂延伸率为20.5%,仍保持有良好塑性。     

904L不锈钢在5g/L H_2SO_4溶液中的腐蚀行为

为了研究904L不锈钢在5 g/L H2SO4溶液中的腐蚀行为,采用动电位极化测试、电化学阻抗测试(EIS)和X射线光电子能谱(XPS)研究其腐蚀行为,并分析其钝化膜的组成.结果表明,904L不锈钢极化后会发生自钝化,钝化区间为-0.2~0.6 V,电荷传递电阻为4 801Ω/cm2,表明904L不锈钢具有较强的耐蚀性能.X射线光电子能谱(XPS)研究表明,钝化膜主要成分为Cr2O3、Cr OOH、Cr(OH)3等化合物.因而904L不锈钢在5 g/L H2SO4溶液中可以表现出良好的耐蚀性能.     

温度对316L不锈钢在3.5％NaCl溶液中腐蚀行为的影响

采用动电位极化和电化学阻抗等方法,研究了在质量分数为3.5%的NaCl溶液中温度对316L不锈钢(316L SS)腐蚀行为的影响,采用Mott-Schottky316L SS腐蚀后的表面形貌。结果表明,在质量分数为3.5%的NaCl溶液中,随着温度的逐渐升高,316L SS在该溶液中的开路电位和腐蚀电位逐渐变负,自腐蚀电流密度逐渐增大,钝化膜电阻和点蚀电位也逐渐减小。对表面腐蚀形貌进行观察的结果表明,随着温度的升高,316L SS表面腐蚀坑直径逐渐增大,数量逐渐增多。这主要因为温度的升高降低了316L SS表面钝化膜的致密度,增大了表面钝化膜的溶解速度,使其抗腐蚀性能下降。     

激光扫描角度对316L不锈钢成型件拉伸性能和致密度的影响

在不同的激光扫描角度下,利用选择性激光熔化成型技术成型316L不锈钢试件,探究试件的拉伸性能(抗拉强度和延伸率)和致密度,并对成型试件进行表面微观形貌和断口形貌的观察。实验结果表明:当激光扫描角度每层旋转15°时,成型试件的抗拉强度、延伸率和致密度均较优,成型件表面形貌平整,无明显缺陷,晶粒细小均匀;激光扫描角度每层旋转0°时,成型试件的抗拉强度、延伸率和致密度较差,成型件表面缺陷较多;成型件断裂方式为韧性断裂。     

Passivation Mechanism of 316L Stainless Steel in Oxidizing Acid Solution

The compositions and the chemical valence states of elements of 316L stainless steel passive film formed in the oxidizing acid solution were studied by X-ray Photoelectron Spectroscopic (XPS) analysis. The electrochemical polarization curve was measured. The passivation process in the oxidizing acid solution was studied by AC impedance technology. The results indicated that the stable compounds layer was formed on the surface of the sample and the adsorption was the main step in the nitrite solution during passivation process. The catalysis passivation mechanism was put forward according to the experimental results. During passivation process, the water molecule was adsorbed on the surface of the sample at first in the oxidizing acid solution. The oxidizer in the solution played a role as catalyst. The oxide and hydroxide, which could be changed each other and finally formed stable passive film, were generated from adsorbing intermediate under the catalytic action. The mathematical models for predicting the steady polarization curve and the AC impedance spectra at certain conditions have been obtained. The passivation mechanism of 316L stainless steel in the oxidizing acid solution can be interpreted by the catalysis passivation mechanism.     

烧结温度对不锈钢（316L)致密性及强度的影响

以不锈钢粉为原料,经１００ＭＰａ冷成型于空气中以不同温度烧结,通过测定其相对密度,线收缩率和抗弯强度、研究温度对材料致密化和强度的影响,结果表明：烧结温度升谪,相对密度和抗弯强度增加,温度超过１２００℃时两者的增加趋于平缓。     

不锈钢表面羟基磷灰石涂层的溶胶凝胶法制备

在316 L不锈钢基体表面采用溶胶-凝胶法和多次提拉法涂覆羟基磷灰石(HA)涂层,并对涂层进行了物相、形貌、结合力和耐腐蚀性能的表征,研究了不同退火温度对涂层性能的影响.结果表明:经400~500℃退火处理,能形成晶化程度不高、晶粒细小的多孔结构羟基磷灰石涂层;提高退火温度可提高HA晶化程度和界面结合力;HA涂层提高了不锈钢的抗侵蚀能力.     

Electrochemical Method for Evaluating the Passivated State of Medical Stainless Steel 317L

The electrochemical behavior of the medical Stainless steel 317L which is used as in vivo fixation materials has been investigated at different passivated states in several candidate-testing solutions. The potentiodynamic scanning polarizaion technique was employed to measure the polarizaion curves of 317L in 0.9%NaCl solution at 37℃. The results showed that the electrochemical behaviorin 0.9% NaCl solution at 37℃ and in 2% NaCl solotion at 30℃ can be better used to detect and evaluate passivated states and corrosionresistance of 317L. In addition,the pitting potential Eb can be used as a criterion and itS lower limit could be 0.85 V(SEC) for this system.     

模拟海洋大气环境下304光亮不锈钢耐蚀性研究

建立了基于电化学阻抗谱(EIS)及电化学噪声技术(EN)的不锈钢大气腐蚀检测方法.设计并制作了配套的电解池.运用所建立的方法测试并计算得到了光亮退火、传统退火工艺处理的304不锈钢在模拟潮湿海洋大气环境中低频阻抗模值和电位噪声功率密度谱的白噪声水平.结果表明:在模拟近海及海洋大气环境中,不锈钢的腐蚀速率随Cl-浓度的增大而增大,同一浓度下,光亮不锈钢的腐蚀速率明显低于普通不锈钢;白噪声水平随Cl-浓度的增大呈现上升趋势,光亮不锈钢钝化膜的稳定性优于普通不锈钢.显示了光亮不锈钢在近海及海洋大气环境中优异的耐蚀性能.     

Nano-Mechanical Behavior and Nano-Tribological Properties of 316 Stainless Steel

The microstructure and nano-tribological properties of 316 austenitic stainless steel have been investigated by using the in situ nano-mechanical testing system Tribolndenter, in which six different normal forces were chosen to make a scratch and indentation. The results show that the contact depth of the indentation increases with the normal force and material is piled up on the edge of the indentation as plastic distortion. The stable nano-hardness and the reduced modulus of 316 austenitic stainless steel are approximately 6 GPa and 160 GPa, respectively. The friction coefficients of 316 stainless steel with conic-type diamond tip have a typical value of about 0.13, 0.15, 0.17, 0.19, 0.22 and 0.25 when the normal forces are kept at 500 μN, 1000 μN, 1500 μN, 2000 μN, 2500 μN and 3000 μN, revealing an increasing trend with the normal forces. The increase of the friction coefficient in the unloading segment may result from the adhesion force caused by the material piled up.     

Electrochemical Behavior of Antimierobial Stainless Steel Bearing Copper in Sulfate Reducing Bacterial Medium

The electrochemical characteristic of antimicrobial stainless steel beating copper NSSAM3 in sulfate reducing bacterial(SRB)was investigated by electrochemical impedance spectroscopy(EIS)and potentiodynamic polarization.The results show that inoculation of SRB into the culture medium significantly affects the anodic polarization behavior of NSSAM3 and accelerates anodic depolarization process,however, it has little effect on cathodic polarization curves of NSSAM3.Under the same exposure time,the anodic polarization curves of NSSAM3 in culture medium with SRB are in anodic active dissolution state when anodic polarization potential value is below 0 V(SCE),whose anodic polarization current density is bigger than that of in culture medium without SRB.Moreover,when the concentration of Cu~(2 ) in SRB medium increases, anodic polarization current density of NSSAM3 decreases and polarization resistance increases with increasing time.Scanning electron microscope(SEM)observations indicate that SRB unevenly attaches on the surface of NSSAM3,and induces the sensitivity to local corrosion.