06Cr25Ni20焊接工艺研究

通过焊接材料的选择,焊接工艺的调整,对06Cr25Ni20不锈钢焊接热裂纹的防治进行了研究试验,最后得出了06Cr25Ni20应用SMAW、GTAW、SAW焊接方法的焊接工艺措施和焊接工艺参数.     

A stochastic analysis of the effect of hydrostatic pressure on the pit corrosion of Fe-20Cr alloy

The effect of hydrostatic pressure on the pit corrosion behavior of Fe-20Cr alloy was investigated in 3.5% NaCl solution by means of potentiodynamic polarization and potentiostatic technology, and the experiment data was analyzed based on stochastic theory. With the increase of hydrostatic pressure, the pit corrosion resistance of Fe-20Cr alloy was deteriorated, which was distinguished by the decrease of critical pit potential (E_cirt) and the increase of passive current density. The results also demonstrated that there exist two effects of hydrostatic pressure on the corrosion behavior of Fe-20Cr alloy: (1) the pit generation rate was evidently increased compared to that under lower hydrostatic pressure, and the metastable pits become faster and larger. However, it seemed that pit generation mechanism shows no hydrostatic pressure dependence; (2) the probability of pit growth increased with the increase of hydrostatic pressure, which implied that the metastable pit on Fe-20Cr alloy exhibited higher probability to become larger pit cavity during shorter time interval than that under lower hydrostatic pressure.     

正交实验法研究铝合金上镀硬铬

通过正交实验法,研究了铝合金上二次浸锌法镀铬工艺条件（镀液成分、镀液温度及电流密度）对镀层硬度和光亮性能的影响,确定了获得高硬度及光亮镀层的最佳工艺参数。     

锡铈镍合金电镀工艺实践

本文简要介绍锡铈镍合金电镀工艺。本工艺镀液稳定，电镀层质量好。     

CL-20对硝酸酯炸药性能的影响

以HMX硝酸酯炸药配方为基础,用六硝基六氮杂异伍兹烷(CL-20)部分替代HMX,计算了含CL-20的硝酸酯炸药的密度、爆热和爆速,并与测试结果进行了对比;测试了其机械感度。结果表明,随着CL-20含量的增加,硝酸酯炸药的实测密度、爆热、爆速均明显增加;当CL-20质量分数为50%时,硝酸酯炸药的实测密度、爆热和爆速分别为1.907g/m3、6 826J/g和9 125m/s,撞击感度由34%提高到40%,摩擦感度由28%提高到60%。     

35CrMo和00Cr13Ni5Mo硫化氢环境应力腐蚀开裂

用慢应变速率拉伸实验和U形试样浸泡实验、电化学极化技术并结合微观分析手段,在湿硫化氢介质中研究了35CrMo和00Cr13Ni5Mo两种钢的应力腐蚀开裂行为规律。结果表明,35CrMo和00Cr13Ni5Mo钢在实验条件下均具有一定应力腐蚀开裂（SCC）敏感性,其敏感性随着溶液pH的降低和H₂ S浓度的增大而增大;00Cr13Ni5Mo 在实验条件下抗SCC的能力均高于同条件下的35CrMo,在pH3.0的溶液中,二者性能比较接近,在pH4.5的溶液中,00Cr13Ni5Mo 耐H₂S环境SCC的性能明显提高,高于35CrMo,这主要是因为00Cr13Ni5Mo中的耐蚀合金元素增强了其钝化膜的稳定性、降低了氢脆作用所致。     

ICP-AES分析低合金钢中的Mn、Mo、V、Ni、Al、Cu、Cr元素

用等离子发射光谱法测定低合金钢中的Mn、Mo、V、Ni、Al、Cu、Cr元素,试样用HNO3和HCl在加热条件下分解,经过系列试验,选择仪器的工作条件,进行测定,建立了一套分析方法,经对照分析,分析结果令人满意。本方法快速准确,精密度良好,完全可以满足生产需要。     

电沉积Ni-Fe-P非晶态合金镀层变温晶化的研究

用差热分析的方法研究了电沉积Ｎｉ－Ｆｅ－Ｐ非晶态合金镀层的变温晶化过程。通过实验得出不同铁含量的Ｎｉ－Ｆｅ－Ｐ合金在不同加热速度下的开始晶化温度、结束晶化温度,并计算出其晶化激活能。对不同Ｆｅ含量镀层的晶化激活能进行比较发现,Ｆｅ元素在Ｎｉ－Ｆｅ－Ｐ合金镀层中具有稳定非晶态组织的作用。     

海绵钛中Fe,Ni和Cr杂质引入过程分析

采用Kroll法,以TiCl4和液态金属镁制备海绵钛,对海绵钛分部位取样,对高Fe, Ni和Cr含量样品进行MLA检测,计算Ti?Mg?Fe, Ti?Mg?Ni和Ti?Mg?Cr三元系的混合焓,研究海绵钛中Fe, Ni和Cr杂质的来源及引入过程。结果表明,海绵钛中Fe, Ni和Cr杂质主要来自钢制(1Cr18Ni9Ti)反应容器,其引入经历了在液态金属镁中溶解和与海绵钛合金化两步。当海绵钛于反应器壁处生成后,其与以单质形式溶于液态金属镁中的Fe, Ni和Cr原子结合将杂质富集。采取反应容器镀膜处理、控制反应区温度、使用低杂质含量的液态金属镁、将海绵钛坨底部与边部分离等措施可有效降低海绵钛中杂质含量。     

ZCP—AES分析低合金钢中的Mn、Mo、V、Ni、Al、Cu、Cr元素

用等离子发射光谱法测定低合金钢中的Mn、Mo、V、Ni、Al、Cu、Cr元素，试样用HNO，和HCl在加热条件下分解，经过系列试验，选择仪器的工作条件，进行测定，建立了一套分析方法，经对照分析，分析结果令人满意。本方法快速准确，精密度良好，完全可以满足生产需要。     

OCr18Ni9换热器应力腐蚀开裂失效分析

某厂锅炉给水预热器在投入使用3.5年后,管箱外壁近横焊缝处发现裂纹.该换热器设计材质为0Cr18Ni9,截取含有裂纹的试样,进行化学成分分析、金相分析、硬度检测、拉伸强度测试、裂纹分析和扫描电子显微镜分析.材质Cr元素含量17.75％,硬度306HV10,这两项检测结果不符合GB/T 4237-2007《不锈钢热轧钢板...     

镀镍槽中Cr6+杂质的处理

镀液中Cr^6 杂质会造成镀镍层减薄、镀层脆性增加，采用还原剂处理法和碳酸铅沉淀法去除Cr^6 杂质，并介绍一种商品“镀镍去铬水”。     

8YSZ在NaF-KF熔盐中的热腐蚀行为研究

本文研究了8mol％-氧化钇稳定氧化锆(YSZ)在NaF-KF复合熔盐中的热腐蚀行为,通过腐蚀前后表面形貌和截面形貌以及成分的对比,分析总结了温度和时间对YSZ的耐腐蚀性能的影响,并结合腐蚀前后XRD的结果,初步探讨了YSZ的热腐蚀机理.结果表明,样品表层在熔盐作用下,主要发生晶界腐蚀;稳定元素的溶出使得样品表层发生相变,加剧了腐蚀行为.截面形貌及成分结果表明样品腐蚀仅有几十微米,且失重小,揭示8YSZ具有良好的耐腐蚀性.     

Zn-Ni合金镀层中Ni含量影响因素及镀层耐蚀性

研究了碱性Zn-Ni合金电镀工艺,采用扫描电镜、极化曲线、交流阻抗及浸泡试验测定了镀液温度、电流密度及镀液组成等因素对镀层表面形貌、镀层中Ni含量及耐蚀性能的影响.结果表明:温度和电流密度对镀层中Ni含量的影响不大;镀层中Ni含量随着镀液中Ni2+与Zn2+质量浓度比的升高而增大.随着镀层中Ni质量分数的增加,镀层颗粒越来越细致、均匀;在5%NaCl溶液中的电化学腐蚀行为表明:Ni的质量分数为13%的合金镀层具有最佳的耐蚀性.     

06Cr19Ni1O与Q235B的焊接工艺

承接了某公司PVC装置上的5台气体密封罐制造.其中罐顶材料为06Cr19Ni10,罐体加强箍为Q235B,两者相焊.第一台气体密封罐在焊接时出现了裂纹.后来调整了焊接工艺,顺利完成了其余4台设备的焊接,质量完全符合要求.     

烧碱蒸发器1Cr18Ni9Ti管污垢热阻的特性

按正交实验方法,在NaCl晶体质量浓度为60、40、15 kg/m3,温度为42、70、85 ℃,速度为2.5、2.0、1.5 m/s的9种不同组合工况下研究了烧碱蒸发器1Cr18Ni9Ti换热管污垢热阻的特性.结果表明:1Cr18Ni9Ti换热管污垢的热阻随时间的延长曲线呈渐近线,且没有明显的诱导期;流速对污垢热阻的影响最大,其次是浓度.通过回归分析,得出了污垢预测模型.     

Electrochemical corrosion performance in 3.5% NaCl of the electrodeposited nanocrystalline Ni films with and without dispersions of Cr nanoparticles

Nanocrystalline (nc) Ni films with and without dispersions of Cr nanoparticles were electrodeposited from a nickel sulfate bath. The grain size of the nc-Ni films was reduced with increasing in the co-deposition content of Cr nanoparticles. Potentiodynamic polarization tests showed that increasing in the co-deposition content resulted in an enlarged passive region of the nc-Ni in 3.5% NaCl through reducing the corrosion potential and increasing the breakdown potential. Scanning electron microscopy (SEM) observation indicated that the polarized pure nc-Ni film exhibited numerous large and deep pits. However, they became smaller and shallower when 4.5 wt.% Cr nanoparticles were co-deposited, and almost disappeared when 10.9 wt.% Cr were co-deposited. X-ray photoelectron spectroscopy (XPS) analysis showed that the different electrochemical corrosion performance was associated with the ability of the Cr nanoparticles co-deposited nc-Ni film to form a continuous Cr-oxide passive film.     

0Cr18Ni9不锈钢管件腐蚀开裂原因分析

通过查找相关材质和施工资料及金相与化学元素分析,找出了聚氯乙烯项目试车前和试车过程中0Cr18Ni9不锈钢管件腐蚀开裂的原因：①采购的0Cr18Ni9不锈钢管件不符合设计要求;②试压水不符合要求,氯离子含量超标,且试压水未及时排放;③缺少有效的监督管理。     

定膨胀铁镍合金碱性化学氧化工艺研究

采用高温碱性化学氧化工艺的方法，定膨胀铁镍合金可获得外观质量好、结合力强、光反射率低、耐紫外线辐射的性能。     

Synthesis and optical properties of Ni/Co/Cr doped BaMg6Ti6O19

Novel green and blue chromophores based on Ni/Co/Cr doped BaMg₆Ti₆O₁₉ solid solutions are successfully synthesized through a solid-state reaction. The crystal structure of all the samples belongs to the magnetoplumbite structure with the space group of P6₃/mmc. The BaMg_6-x/2Ti_6-x/2Ni_xO₁₉ (0 ≤ x ≤ 0.3) compounds exhibit a light green (x = 0.1) to yellow-green (x = 0.3) color. The oxidation state of Ni is confirmed to be +2 valence and the d-d transition of Ni²⁺ in octahedral sites is responsible for color. BaMg_6-x/2Ti_6-x/2Co_xO₁₉ (0 ≤ x ≤ 0.3) series show a blue color and the intensity of blueness is increasing with the increase of Co content. The blue color is due to d-d transitions within Co²⁺ present in the tetrahedral sites. For BaMg_6-x/2Ti_6-x/2Cr_xO₁₉ (0 ≤ x ≤ 2) phases the color varies from light green (x = 0.2) to green (x = 2). Chromium exists in +3 and + 6 oxidation states and the observed color is due to charge transfer transition between Cr³⁺–Ti⁴⁺ and d-d transitions within octahedral Cr³⁺ sites resulting in strong absorption in the visible region. The synthesized colored oxides are mixed with PMMA to prepare novel green and blue PMMA polymer composites to evaluate their compatibility in plastics.