管接头专用焊条GJ506的研制

本文提出了对管道焊接专用焊条ＧＪ５０６的研制要求，详细介绍了研制该焊条所采取的技术措施。通过各项试验，表明该焊条的研制达到了预期的目的，各项性能优良，工艺评定合格。在管道焊接中较普通Ｊ５０６、Ｊ５０７焊条在工艺上具有明显优势，对提高管子焊接质量，加快工程进度，具有重大的技术经济意义。     

从对标准的质疑谈复合钢焊条电弧焊的工艺要点

复合钢的焊接包括异种钢和同材质钢的焊接，而又具有其本身的焊接特性，因而对复合钢焊接工艺必须认真对待。设计合理的接头形式；正确选用焊接材料、按照合格的焊接工艺评定确定焊接工艺参数；并按合理的焊接顺序进行焊接操作可以较好地保证焊缝质量，形成高质量的焊接接头，对不合格焊缝的返修，其工艺因复合钢的特殊性有与一般焊接焊缝返修不同的要求，负责复合钢焊接的技术人员一定要慎重，同时注意不同阶段无损检测的完整性和严密性。     

40Cr气缸缸体与35钢法兰的焊接

本中心为某卷板机焊接气缸,气缸缸体材质为40Cr,两端装有法兰板,材质为35钢,焊接结构如图1a所示。此结构焊接后需对气缸内孔及法兰进行机械加工,同时还要保证气缸能够承受10MPa压力,因此不仅要避免在焊接过程中产生缺陷,同时还要保证焊件焊后的机械加工性能。本文通过对2种钢材的焊接性分析,选择了合适的焊接材料、合理的焊接工艺及焊后热处理措施,满足了构件的使用要求。     

焊条电弧焊补焊时焊接工艺的选择

焊接工艺的选择主要是根据被修复件的材质,补焊部位和要求,选用合适的焊接方法,制定合理的工艺(设备、材料、坡口形式、焊层、焊道、焊接顺序、焊接参数、热处理工艺等)。坡口形式要根据待补焊部位的几何形状,制定坡口的加工方法,以保证缺陷全部清除为标准;坡口形式的确定以损坏部件易于焊透,且尽量少消耗焊条为目的,另外还要考虑焊后的加工和工件的变形,还要根据工件要求进行适当清理。焊接工艺参数的选择包括焊条种类、牌号、规格、焊接电流的种类及极性,电弧电压、焊接速度、焊层、焊道及热处理工艺。①根据被焊母材的需要,选…     

机车油箱补焊工艺

针对机车油箱漏油在机务段维修补焊难题,通过分析造成油箱漏油的缺陷及现场情况,制定了合理的焊接工艺并实施,总结了一套焊补油箱的工艺操作方法。结果表明:选择正确的焊接参数、坡口形式和焊条电弧焊断弧焊的焊接工艺补焊油箱,完全能够满足油箱结构的设计及使用要求。     

手工自蔓延焊条的焊接工艺性

以3 mm厚Q235钢板为焊接母材,研究了手工自蔓延焊条成型工艺参数之一的混粉时间对焊条燃烧速度的影响,在使用小型高速混料机的情况下,混粉时间约60 s时焊条燃烧速度平稳、合适,发热量大,可控性良好;针对手工自蔓延焊条的焊接工艺特点,系统地探讨了焊接工艺参数对焊缝成形和焊接效果的影响,得到的最佳焊接工艺参数为:焊接方向采用后倾,焊接倾角约70°,焊条焰长5 mm,焊接速度7～9 mm/s。在此焊接工艺参数条件下,焊缝成形良好,外观平整光滑,焊道宽度均匀,达到单面焊双面成形的效果。     

向下焊在萧-甬长输管线焊接中的应用

对有缝钢管L290向下焊工艺性研究及按国家石油天然气SY4052－92标准进行焊接工艺评定,制定出合理的焊接工艺规程,运用于萧－甬长输管线焊接施工中,取得了良好的效果,由此证明了该工艺是一种焊接质量高、经济性能好、生产效率高的焊接工艺方法。     

长输管道向下焊焊接工艺

介绍了手工向下焊焊接工艺在长输管道焊接方面的发展，主要离混合型向下焊焊接工艺和复合型向下焊焊接工艺的应用。     

海洋平台桩腿用E690高强度淬火回火钢焊接工艺研究

针对用于海洋平台桩腿的CCS E690级别焊接结构用高强度淬火回火钢进行焊接工艺研究,对该材料的化学成分和力学性能进行研究和分析,参考生产厂家推荐的焊接工艺参数,分别采用焊条电弧焊和埋弧焊两种焊接方法制定合理的焊接工艺认可方案,根据焊接工艺认可方案实施,试验结果证明该方案合理可行。     

40Cr/55Si2Mn钢的焊接工艺改进

在对40Cr/55Si2Mn钢焊接性分析的基础上，进行了多种焊条和焊条组合的焊接工艺对比试验，并对焊缝和接头进行了相应的性能测试和显微组织观察。结果表明：在合适的焊接工艺条件下，用A137焊条替代A146焊条焊接40Cr/55Si2Mn钢是可行的。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

THERMODYNAMICS STUDY ON THE DECOMPOSITION OF CHROMITE WITH KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

INFLUENCE OF HEAT TREATMENT ON DAMPING BEHAVIOUR OF THE MAGNESIUM WROUGHT ALLOY AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.