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1.
以Q235钢材原件、热熔浸铝一次和两次的Q235钢为研究对象,通过模拟海水(质量分数为3.5% NaCl溶液)浸泡试验,对比研究了3种试样在NaCl溶液中的腐蚀行为。利用扫描电镜观测了不同样品在腐蚀前后的表面形貌,利用失重法、交流阻抗等方法研究了热熔浸铝Q235钢的腐蚀速率。结果表明,在NaCl溶液中Q235原件腐蚀速率最快,腐蚀严重,年均腐蚀速率为0.11 mm/a;热熔浸铝一次和两次的Q235钢腐蚀速率相差不大,年均腐蚀速率分别为0.04和0.03 mm/a,热熔浸铝后Q235钢的耐腐蚀性能明显得到提高,说明热熔浸铝是一种有效提高Q235钢耐海水腐蚀性能的手段。  相似文献   

2.
镍铝青铜合金是铸造大型舰艇螺旋桨的主要材料,海洋污损生物在合金表面附着引起的pH值变化会加速镍铝青铜合金的腐蚀磨损,威胁到舰艇安全航行.采用冷喷涂技术制备了较为致密的镍铝青铜涂层,厚度约300 μm,利用扫描电镜、光学显微镜观察了涂层的微观形貌,重点研究了涂层在pH值分别为3、7和11,质量分数为3.5%的NaCl溶液中的电化学腐蚀性能和腐蚀磨损行为.实验结果表明:pH值为3的环境中,镍铝青铜基体发生了选相腐蚀,表面疲劳裂纹主要分布在富Cu的α相上,涂层上的犁削沟槽加深发生了磨粒磨损,涂层耐腐蚀性能优于基体;pH值为7的环境中,基体发生了黏着磨损,表面有片层状金属剥落,涂层中的孔隙收容了大量磨屑避免了剧烈的三体摩擦,表面犁削沟槽较浅,涂层致钝电位高于基体,耐腐蚀性能变差.pH值为11的环境中,基体发生了表面疲劳磨损,涂层磨痕上有较深的犁削沟槽,沟槽内有微裂纹,涂层耐腐蚀性能优于基体.总体来说,在不同pH值环境中,涂层由于在冷喷涂过程中发生了冷加工硬化并且涂层上的孔隙收容了磨屑,导致涂层的耐腐蚀磨损性能增强.   相似文献   

3.
采用超音速火焰喷涂技术,制备了含Fe、Cr、Mo、Ni、P、Si、B的Fe基非晶合金涂层。利用显微硬度计、扫描电子显微镜、X射线衍射仪、电化学工作站、差示扫描量热仪等设备对涂层的组织结构、耐腐蚀性能和热稳定性进行了研究。喷涂工艺参数为:氧气压力0.6MPa,氧气流量166L·min-1,丙烷压力0.55MPa,丙烷流量24L·min-1,喷涂距离350mm。制备的涂层孔隙率和显微硬度分别为1.8%和823HV0.1,其非晶化程度较高;微观结构分析表明涂层由熔化变形成扁平粒子、未熔化的粉末颗粒以及孔隙、裂纹等缺陷组成的波浪层状组织。相组织结构分析表明涂层主要由非晶相组成,含有少量的纳米晶相组织。差示扫描量热仪测试表明所制备涂层的晶化区间为532℃~580℃。电化学测试表明,Fe基非晶合金涂层在1mol·L-1的H2SO4、10%NaOH和3.5%NaCl溶液中都经历了活性溶解—钝化—过钝化的过程,涂层在NaOH溶液中的耐腐蚀性能最强,其次为NaCl溶液,在H2SO4溶液中的耐腐蚀性能较差。  相似文献   

4.
铝电解电容器用铝箔发孔腐蚀工艺的研究   总被引:1,自引:0,他引:1  
采用电化学方法,找到了阳极发孔腐蚀的影响因素.采用正交实验,研究了HCl+H2SO4体系中腐蚀液组成、腐蚀电流密度、腐蚀温度以及腐蚀时间对铝箔性能的影响.结果表明:当选取ψ(HCl∶H2SO4)为1∶3,电流密度为0.25 A/cm2,腐蚀温度为70℃,腐蚀时间为105 s时,可以获得较优比容的腐蚀箔,比容值为110.8μf/cm2,为铝箔腐蚀的研究提供了一定的科学依据.  相似文献   

5.
锆合金在HCl和H2SO4溶液中的耐蚀性能研究   总被引:1,自引:0,他引:1  
采用化学浸泡、电化学测试和物理检测技术,研究了HCl和H2SO4溶液中锆合金的腐蚀行为.结果表明,锆合金在还原性的HCl和低浓度H2SO4溶液中,具有优异的耐蚀性,而在高浓度的氧化性H2SO4溶液中腐蚀速率显著增大.物理检测结果显示,腐蚀的锆合金表面均匀地覆盖着弥散分布的微小颗粒状ZrO2.还原性的HCl和低浓度H2SO4溶液中ZrO2膜保持了原有的致密性,增强了锆合金的耐蚀性能.而高浓度H2SO4溶液中,在其强氧化作用下,锆合金基体/膜界面处不断生成ZrO2.当膜增加到一定厚度时,氧化膜的晶格参数与金属的晶格参数不一致,产生内应力,降低了氧化膜的附着力,直至氧化膜破裂,露出新鲜的锆合金表面.继之,新鲜的锆合金再次被氧化,以此循环往复,导致锆合金在浓H2SO4溶液中腐蚀加剧.  相似文献   

6.
不锈钢材料在酸溶液中耐蚀性的研究   总被引:5,自引:0,他引:5  
朱龙英 《钢铁研究》2003,31(2):45-48
研究了不锈钢AISI304和1Cr18Ni9Ti在几种酸溶液中的腐蚀特征。这两种不锈钢在HNO3,H2SO4,H3PO4溶液中腐蚀轻微,主要是晶间腐蚀;而在HCl溶液中腐蚀严重。以点蚀为主。不锈钢AISI304的耐蚀性优于1Cr18Ni9Ti,不锈钢中碳的质量分数越低。其耐蚀性能越好。  相似文献   

7.
本文采用两种Fe基非晶合金粉末,通过大气等离子喷涂工艺制备非晶涂层。其中一种含有10%P元素(编号Fe-P),另一种含有10%W元素(编号Fe-W),且二者其他化学成分相同。通过电化学工作站对涂层分别在酸、碱、盐腐蚀介质中的耐蚀性能进行了研究。研究表明,Fe-W与Fe-P涂层在1mol/LH2S04溶液中的耐蚀性能相当,而在10%NaOH溶液中Fe-W涂层的自腐蚀电位提高了135mV;在3.5%NaCl溶液中Fe-W涂层的自腐蚀电位提高了358mV,并且产生了耐氯离子腐蚀的钝化膜,耐腐蚀能力优于Fe-P涂层。  相似文献   

8.
《中国钨业》2016,(2):43-48
研究了钨碱性萃取过程中铝的存在形态、行为及对钨萃取的影响以及不同洗涤剂对负载有机相中铝的洗脱率效果。结果表明,(R4N)_2CO_3优先萃取钨酸根离子,当料液p H13,WO_3浓度95 g/L,铝浓度低于20 g/L,萃取相比O/A=1.2∶1时,W/Al分离系数达到72以上;当铝浓度2.7 g/L,WO_3浓度低于117 g/L,萃取相比O/A=1.2∶1时,W/Al分离系数超过31.5。料液中的铝浓度变化对钨的萃取率没有明显影响,铝的萃取率在10%左右;采用0.1 mol/L的碳酸钠溶液作为洗涤剂时,铝的单级洗脱率可达75%;对于串级萃取、洗脱铝的载钨有机相,采用3 mol/LNH_4HCO_3+1 mol/L NH_3·H_2O为反萃剂,相比O/A为1.2∶1时,钨的反萃率达到93%以上,反萃获得的钨酸铵溶液中未检测到铝。  相似文献   

9.
采用不同浓度的盐酸溶液对HY沸石进行脱铝改性,利用XRD、TGA等分析手段对所制备样品的物相、结构等进行表征分析,研究了样品对CO2/H2O的吸附性能.结果表明:采用浓度为0.5 mol/L的盐酸溶液对沸石HY进行脱铝改性后,材料仍然具有较完好的晶体结构,在保持较高CO2吸附能力的同时疏水性能得到明显改善.  相似文献   

10.
为改善铝阳极的性能,选用工业纯铝(99.8%),熔炼了Al-0.1 In-0.1 Ga-3Ph合金.在4 mol·L-1 KOH溶液中添加znO,KMnO4,Na2SnO3·4H2O,C4H4O6KNa4H2O,研究添加剂对合金阳极行为的影响.结果表明:溶液中添加znO后合金的析氢腐蚀得到明显的抑制,同时降低了合金的极化;KMnO4的加入可大幅提高合金的开路电位,但对抑制合金析氢腐蚀作用不明显;Na2SnO3·4H2O可提高合金的开路电位,降低极化.复合添加剂(11 mmol·L-1ZnO+0.61 mmol·L-1KMnO4)使合金开路电位负移,并有效抑制其析氢腐蚀,提高了阳极活性,综合性能较佳.  相似文献   

11.
转炉炉壳热应力分析   总被引:5,自引:1,他引:4  
任学平  郭志强  邹家祥 《炼钢》2001,17(6):47-49
根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。  相似文献   

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通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。  相似文献   

14.
Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.  相似文献   

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Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

17.
The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.  相似文献   

18.
Usage of quality of life of psychiatric patients' relatives as the parameter of estimation of the quality of psychiatric care is considered. By means of standard questionnaire elaborated by the authors as well as by means of both individual and group conversations the quality of life was analyzed in 40 relatives which lived together with psychiatric patients. Different spheres of their life and difficulties (financial, social-psychologic, production) were examined in families with such patients. The defects of psychiatric care that had direct influence on the quality of life of the psychiatric patients' relatives are outlined.  相似文献   

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