45CrNiMoVA钢的预先热处理和预冷淬火工艺

研究45CrNiMoVA钢的预先热处理、预冷淬火工艺对组织、力学性能及畸变量的影响.结果表明,试验钢采用正火-低温退火工艺,可以细化晶粒,减小畸变量,保证了45CrNiMoVA钢坯有良好的切削加工性,提高了钢件的冲击韧性.采用预冷淬火的调质处理工艺能将工件淬硬,获得了需要的索氏体组织,且晶粒进一步细化;45CrNiMoVA钢的屈服强度、抗拉强度、冲击韧性均较常规淬火工艺的高;焊缝力学性能与母材基本相符,焊缝中心区组织为均匀细小的索氏体组织;壳体焊接结构试验件经预冷淬火的调质处理后,畸变明显减小.     

公路桥梁钢的焊接行为与性能研究

在相同电子束焊接工艺下,对比分析了不含Nb和含Nb桥梁钢的母材和焊接接头显微组织以及力学性能,并对含Nb钢焊接头和母材的耐腐蚀性能进行了研究。结果表明,在相同的电子束焊接工艺下,不含Nb的钢的热影响区和焊缝区的晶粒尺寸较为粗大,而在钢中添加Nb元素后,热影响区等轴晶和焊缝区柱状晶尺寸都变小。含Nb焊接接头的抗拉强度和断后伸长率都要高于相同焊接工艺下的不含Nb钢焊接头。     

1Cr13和ZG15Cr2Mo1异种钢真空电子束焊接实验研究

选用ZG1Cr13和ZG15Cr2Mo1两种不同铸钢材料,采用真空电子束焊接方法进行实验研究。结果表明:射线探伤检验,中压电子束焊接合格率优于高压电子束焊接;从焊缝宏观缺陷分析,中压电子束焊缝的缺陷数量和种类明显少于高压;从力学性能比较,中压比高压电子束焊接接头力学性能要好,尤其是冲击性能。     

电子束焊接对调质15CrMnMoVA高强钢组织及性能的影响

为实现高淬火倾向的航空高强钢材料的高质量接头,以15CrMnMoVA高强钢为研究对象,进行了电子束焊接工艺试验研究;针对不同结构的电子束焊接接头,分析了焊缝显微组织特征、焊接接头的显微硬度分布和力学性能,探讨了电子束焊接工艺对接头组织性能的影响。结果表明,15CrMnMoVA钢的焊缝中心形成了网篮状马氏体组织,其显微硬度为典型的马鞍形分布。不同锁底结构的电子束焊接接头的拉伸性能基本都与母材相当,但其疲劳性能差异明显,锁底长度为1.5 mm时焊接接头的疲劳性能较好。     

9Ni钢焊条电弧焊工艺试验

分析9Ni钢的焊接难点、热处理工艺及匹配焊接材料选择,并对9Ni焊条电弧焊进行了工艺试验,通过对焊后材料进行无损探伤及力学性能试验,得出了最佳焊缝机械性能所对应的焊接参数。为液货储罐焊接施工提供了技术参考。     

30CrMoV9钢真空电子束焊接

针对28 mm厚30CrMoV9钢进行真空电子束焊接,通过焊前预热、焊后缓冷来避免焊缝焊接气孔、裂纹的产生。焊接接头的组织、性能试验结果表明,通过选择合理的焊接工艺参数,采用真空电子束焊接30CrMoV9钢能够获得良好的力学性能。     

35CrMnSiA钢与06Cr19Ni10钢焊接工艺研究

文中通过模拟35CrMnSiA钢与06Cr19Ni10钢焊接过程,焊接方法采用焊条电弧焊,焊接材料选用A507焊条,焊前对工件进行预热,焊后对工件进行了后热及探伤,分析和研究了焊缝的力学性能和金相组织。通过试验得出：A507焊条的焊接工艺参数满足焊缝设计要求,可以推广应用到公司其他相关产品的生产中。     

装甲钢的焊接工艺

正装甲钢特别是高硬度装甲钢C616及C685已广泛应用于军工产品生产中,近几年,该材料也陆续应用到本公司相关产品上,均采用焊接进行连接。但该材料焊接性差,极易产生焊接裂纹,因而探索合适的焊接工艺,避免产生焊接裂纹等缺陷显得十分重要。本文主要对试件焊接工艺及工艺参数进行试验,并通过焊接接头的力学性能分析及焊缝探伤检测,     

HG785D薄壁槽形件对扣焊接工艺

研究HG785D薄壁槽形件对扣焊接工艺,分析总结出一套关于HG785D薄板焊接的较为合理的焊接工艺规范,可减小薄壁件焊接存在的复杂、多元变形,达到单面焊接双面成型。有效地解决了薄壁梁焊接存在的技术难题,保证焊缝射线探伤一次检验合格。对焊缝进行力学性能试验。结果表明焊缝的强度、冲击功均超过基材,强度达到Ⅰ级要求。焊接工艺经多次检验效果良好,为低合金高强钢薄板焊接提供了技术支持。     

大厚度K4169高温合金电子束焊接工艺

通过对大厚度K4169合金真空电子束焊接工艺试验研究,优化了工艺参数,分析了焊缝表面成形及焊接接头组织、力学性能。结果表明:K4169合金具有良好的电子束焊接性能,焊缝区形成层状组织,时效处理后焊缝抗拉强度远远高于母材的抗拉强度。     

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.     

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.     

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。     

A STUDY OF TEMPERATURE-DEPENDENT VALENCE BOND STRUCTURE OF TITANIUM

On the basis of energy and shape method for the determination of the valence bond (VB) structures of crystal, the valence bond structure of titanium is redetermined at room temperature and calculated in the whole temperature range of 0-1943K. The outer shell electronic distribution of Ti is e_c~(2.9907) · (s_c~(0.4980) d_c~(2.4927)) ef1.0093 in crystal. The temperature dependences of the VB structures of hcp and bcc phases are the same. The VB structures of hcp and bcc phases monotonically increase or decrease with the increase in temperature, but show discontinuous changes at the phase-transformation temperature 1155K.