拉制SUS310STPZGCr25Ni20铸造弯头焊接工艺研究及现场焊接

近年来,国产或引进的Cr25Ni20耐热钢制容器和管线等装置,因焊缝含碳量较低引起的焊接时或长期高温运行时的沿晶热裂纹时有发现。本文研究讨论了改用镍基焊材焊接时的焊接工艺及接头的使用性能。现场焊接令人满意。     

14Cr1MoR+022Cr17Ni12Mo2复合材料的焊接结构及焊接工艺

煤化工激冷罐的壳体材料采用14Cr1Mo R+022Cr17Ni12Mo2复合板,板材较厚,焊接难度较大。通过分析研究和焊接工艺试验,确定了适合的焊接方法、焊接材料、焊接坡口、焊接顺序以及热处理工艺,有效地避免了焊接过程中基层对复层的稀释作用和碳迁移,显著地提高了整个设备焊缝的焊接质量,取得了良好的效果。     

00Cr18Ni5Mo3Si2+Q235复合不锈钢板的焊接

复合不锈钢以其良好的使用性和经济性被广泛应用于炼油和石化装置防腐耐高温压力容器和管道中。分析了复合不锈钢板其中一种 0 0Cr1 8Ni5Mo3Si2 +Q2 35的焊接性能 ,进行了焊接工艺试验 ,制定了合理的焊接工艺措施 ,在实践中取得了良好的效果     

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.     

1Cr5Mo炉管的焊接施工

由于 1Cr5Mo具有高的空淬特性和较大的焊接冷裂纹敏感当量 ,致使焊接易产生冷裂纹和淬硬组织。本文介绍了 1Cr5Mo炉管的焊接工艺、焊接施工程序、工艺要点以及焊接检验要求等。并通过实践取得了良好的焊接效果。     

Cr5Mo合金钢的焊接工艺

Cr5Mo钢是以铬钼为基本合金元素的合金钢,其金相组织为珠光体,具有优良的耐高温硫腐蚀性、耐氧化性及较高的高温强度,但Cr5Mo钢焊接性差。本文分析了Cr5Mo钢的冷裂纹倾向和再热裂纹敏感性及产生缺陷的原因,并提出了相关工艺及施工中的注意事项。     

奥氏体不锈钢000Cr25Ni20焊接工艺研究

介绍了在国产核燃料后处理关键设备上使用的高纯级奥氏体不锈钢000Cr25Ni20钢的力学性能、化学成分和耐腐蚀情况。通过对该钢的焊接方法、坡口形式、焊前准备、焊接工艺参数的研究,为高纯奥氏体不锈钢000Cr25Ni20的焊接奠定了基础,并成功应用到设备的制造中。     

1Cr5Mo耐热钢管的焊接

对1Cr5Mo耐热钢管的焊接性进行分析,制定合理的焊接工艺,获得了质量良好的焊接接头。     

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.     

12Cr2AlMoV钢换热器芯子焊接制造

管板为 1 6Mn锻件基体上爆炸复合 1 2 Cr2 Al Mo V薄板 ,换热管为1 2 Cr2 Al Mo V。对该换热器材料的特性进行了分析 ,进行了焊接试验和焊接工艺评定 ,并以此为依据制定了焊接工艺 ,解决了 1 2 Cr2 Al Mo V钢换热器芯子的焊接制造问题。     

镀铬情缘

邮局送来一本刚出版的电镀刊物,我随手翻阅起来,一篇文章引起我高度关注,反复看了两遍,它传递的信息使我大为惊讶。说的是镀铬溶液,文章是这样写的：“……有些中小企业没有化验条件,对硫酸含量只凭估计,又担心估计不够确切,所以干脆采取加过量的碳酸钡将硫酸全部沉淀掉,过滤后再准确地加入所需硫     

两种不锈钢冲刷腐蚀的研究

用板状试样在料浆罐式冲刷腐蚀实验机上研究了两种不锈钢的冲刷腐蚀规律。结果表明,力学性能只在冲刷速度高时才对材料耐冲刷腐蚀性有显著作用,在冲刷速度高时,２Ｃｒ１３的冲刷腐蚀失重比１Ｃｒ１７Ｍｏ２低;而在冲刷速度低时（２ｍ／ｓ）,１Ｃｒ１７Ｍｏ２的冲刷腐蚀失重比２Ｃｒ１３的低。材料的力学性能也影响其在不同冲刷角度时的冲刷腐蚀规律。２Ｃｒ１３的冲刷腐蚀失重随冲刷角度增大而单调增加,在冲刷角为９０°时最大。１Ｃｒ１７Ｍｏ２的冲刷腐蚀失重在３０°左右时出现峰值,在９０°时为最大。两种材料的纯冲刷失重随冲刷角度的变化与冲刷腐蚀失重的变化类似。     

Sintering additives regulated Cr ion charge state in Cr doped YAG transparent ceramics

Cr: YAG and Cr, Nd: YAG transparent ceramics have significant application prospects in solid state lasers, therefore a controllable charge state of Cr ion in Cr doped YAG transparent ceramics is necessary. In this study, a successful regulation of Cr charge state in both Cr, Nd: YAG and Cr: YAG transparent ceramics was achieved, by a simple optimizing the sintering additives. Both ceramics with the Cr doping concentration of 0.3?at% reached to the theoretical transmittance, after the vacuum sintering and the subsequent annealing process. It was found that by adopting silica additive, divalent charged Cr²⁺ ions could be detected from the vacuum sintered samples, and they were transferred into trivalent state after further annealing in air. Meanwhile, by vacuum sintering ceramics with divalent additives (CaO and MgO), a stable trivalent charged Cr ion could be obtained, and the subsequent air annealing process indicated a significant conversion from Cr³⁺ to Cr⁴⁺. Further increasing the Cr concentration was not benefit to the optical quality as well as the conversion of Cr³⁺ ion in Cr, Nd: YAG transparent ceramics.     

土壤-植物系统中的铬

介绍了土壤环境中铬的来源及其迁移转化积累，分析植物对铬的吸收和积累，以及探索铬在植物生长发育中的作用和对土壤-植物系统的影响。     

多层镀镍／铬

1　概述随着我国汽车、摩托车行业迅速发展 ,对表面处理也提出新的标准 ,但采用铜 镍 铬电镀工艺远远不能满足生产发展的需要。由于铜 镍 铬体系不存在 10 0ｍＶ左右电位差 ,因而不具备电化学保护作用。因此 ,腐蚀过程一直向纵深方向进行 ,使铁基体很快腐蚀。所以要解决这一问题 ,电镀工艺必须采用多层镍体系 ,由于半亮镍和光亮镍组成的双层镍之间具有 10 0ｍＶ左右的电位差 ,因而在腐蚀过程中发挥电化学保护作用 ,要比铜 镍体系优越 ,质量要求更高的产品须采用三层镍体系 ,其实质是在半亮镍和光亮镍层之间镀一薄层 (1μｍ左右 )高硫镍 ,这…     

一次镀铬故障处理

我厂使用标准镀铬液镀铬,最近镀铬波动大,深镀能力变化大,难以琢磨。刚调整好的槽液,经几天电镀后就无法镀零件,严重影响了产品质量和生产进度。经过仔细观察,终于找到了故障原因,并将故障排除。1　镀铬工艺配方及操作条件　　ＣｒＯ3,ｇＬ200～250Ｈ2ＳＯ4,ｇＬ2.0～2.5Ｃｒ3+,ｇＬ2～4Ｔ,℃48～55Ｄｋ,Ａｄｍ225～30阳极铅棒2　故障现象　　零件镀镍后表面光亮正常,镀铬后,零件的孔眼周围及折弯部位出现了“露黄”。3　故障排除　　针对故障现象,加强了对镀铬槽的维护。将铅阳极全部进行刷洗,控制好槽液温度及电流密度并进行电解活化,然后…     

镀铬阳极选用

简要分析了阳极材料及阳极面积对镀铬溶液及镀层性能的影响。设计出一种简单实用的、符合镀铬工艺特殊要求的窗格式镀铬阳极。介绍了这种阳极的优点及El常维护。     

Phase stability and weak metallic bonding within ternary-layered borides CrAlB,Cr2AlB2, Cr3AlB4, and Cr4AlB6

To explore the potential for use of the Cr–Al–B borides, Cr₂AlB₂, Cr₃AlB₄, and Cr₄AlB₆ as well as hypothetical CrAlB are investigated using density functional theory. In the CrAl(CrB₂)_n series strong covalent bonding is present between the B and Cr atoms with, significantly, much weaker metallic Cr–Al and B–Al bonds, suggesting similar unusual properties to the MAX phases. The relative stiffness of the weakest and strongest bonds hint at similar unusual properties to the MAX phases with superior damage tolerance expected for hypothetical CrAlB, as evidenced in the lowest Al1–Al2 bond stiffness. The layered nature and metallic bonding are expected to result in high fracture toughness and damage tolerance. Anisotropic compression is demonstrated, with the stiffest axes along the direction of the B–B zigzag-/hexagonal-chains and the softest axes determined by an interplay between the soft metallic interlayers and the rigid covalent bonds. In general the elastic moduli in CrAl(CrB₂)_n increase as a function of n, however, without the price of an increase in density.     

Interactions of Cr(VI) and Cr(III) with isolated rat liver mitochondria

The mechanism of interaction of Cr(VI) with isolated rat liver mitochondria was investigated in this study. The results suggest that Cr(VI) induces the opening of the membrane permeability transition pore (MPT). The phenomenon is cyclosporine-sensitive and is in agreement with the cyclosporine-sensitive apoptosis observed in the cells incubated with this compound. Moreover the action of Cr(III), that is formed in the cells by a reduction of Cr(VI), has been also analysed. The results obtained demonstrated that the Cr(III) does not induce the opening of the MPT in isolated mitochondria, but it has a protective effect in preventing Cr(VI) MPT opening. Therefore, these results suggest that apoptosis is regulated by a balance between Cr(VI) accumulation in the cytoplasm and Cr(III) formation.     

Sand erosion and crack propagation mechanism of Cr/CrN/Cr/CrAlN multilayer coating

Herein, we have deposited Cr/CrN/Cr/CrAlN multilayer coatings with various modulation ratios on TC11 alloy substrate using cathodic arc system. The influence of various modulation ratios on microstructure and Al₂O₃ sand erosion behavior of coatings is systematically studied. Results reveal that the coatings are about 200 nm per cycle and total thickness is 8 μm. Five groups of coatings exhibit high hardness (>3000 HV_0.025). The coating with modulation ratio of 12 adhesion can reaches 55 N. The residual stress increases with the decrease of the modulation ratio, but the increase is generally low (less than ?2 GPa). In addition, according to sand erosion test, it is found that sand erosion resistance of multilayer coating is significantly around 5 times higher than TC11 alloy matrix. The erosion morphology shows that a large number of irregular cracks and layered spalling appear on the surface of the coating, indicating that the cracks are constantly initiated under the continuous impact of the sand and gravel，and finally gather together and then spalling. Moreover, dynamic response and stress field of the coating under the impact of single sand (Al₂O₃) are studied by numerical simulations. It is determined that coating cracking is caused by high tensile stress under CrAlN layer. In addition, according to crack propagation morphology and influence of different interfaces between multilayered structures on crack tips, propagation/termination mechanism of cracks is analyzed in detail. Cracks are easy to initiate in hard CrAlN layer and consume a lot of energy after propagating into soft Cr layer, thereby ending at next soft and hard interfaces. These results provide experimental and theoretical support for the study of high tenacity and anti-erosion coating.