溶剂淬火低钼Cr20MoCu高铬铸铁锤头的研究

空冷淬火Cr20Mo2Cu高铬铸铁（1．5％～3％Mo），因目前钼铁价格飞涨而使其应用受到限制。介绍了一种低钼高铬铸铁Cr20MoCu（0．5％Mo），它是在Cr20Mo2Cu高铬铸铁的基础上通过降低钼含量而确定的。降钼后对淬透层深度的影响试图采用一种新型水溶性缓冷淬火剂通过提高Cr20MoCu高铬铸铁奥氏体化后的冷却速度来得到补偿，从而实现以低成本的Cr20MoCu代替高成本的Cr20Mo2Cu高铬铸铁的目的。试验结果表明，溶剂淬火低钼高铬铸铁Cr20MoCu的组织、力学性能、淬透层深度与降钼前的Cr20Mo2Cu相当。然而，溶剂淬火低钼高铬铸铁Cr20MoCu只适用于生产重量小于25kg级的小锤头，倘若锤头重量增大，则因淬火应力增加而导致锤头淬火开裂倾向明显增大。     

双相不锈钢15Cr-7.5Mn-2.6Mo的固溶渗氮工艺研究

采用正交实验法研究了 15Cr 7 5Mn 2 6Mo双相不锈钢的固溶渗氮工艺。结果表明 :在压力0 15MPa的高纯N2 气氛中 ,10 5 0℃× 2h +115 0℃× 3h +10 5 0℃× 2h +115 0℃× 4h工艺为最佳工艺 ,按此工艺 ,可获得 1 6 2mm以高氮奥氏体为主的表层。方差分析表明 :渗剂种类对固溶渗氮影响特别显著 ,炉内压力与工艺的影响显著。X射线衍射分析证实固溶渗氮后缓冷试样表层主要物相为 :氮奥氏体、CrN、Fe3O4 和少量氮铁素体 ;固溶渗氮 +固溶处理试样表层为单相氮奥氏体。这说明固溶渗氮是氮在奥氏体的纯扩散过程 ,测得PN2 =0 15MPa、10 5 0～ 12 0 0℃条件下的氮的扩散激活能Q =186 6kJ mol     

热处理对高铬钨铸铁性能的影响

研究了热处理对高铬钨铸铁力学性能的影响,结果表明,高铬钨铸铁经980℃×2h空冷+400℃×2h回火处理可获得较高的力学性能。     

热处理工艺对Cr15高铬铸铁力学性能影响

利用正交试验系统研究了Cr15高铬铸铁中碳及变质剂含量(RE、V、B)、淬火温度、回火温度等因素对Cr15高铬铸铁力学性能的影响,并优化主要合金成分及热处理工艺参数。结果表明:各因素对Cr15高铬铸铁热处理后力学性能影响的大小顺序为:含碳量、回火温度、淬火温度、RE、V、B。优化合金成分结果为C=2.9%,RE=0%、V=0.3%、B=0%。最佳热处理工艺为:淬火温度980℃,保温3 h,空冷;回火温度450℃,保温3 h,空冷,对应Cr15高铬铸铁力学性能为:硬度59.8 HRC,冲击韧度9.70 J·cm-2。     

高铬铸铁叶片的热处理工艺

对挖泥船泥浆泵叶片用高铬铸铁的热处理工艺进行研究。结果表明,在奥氏体化温度分别为800、900、1000和1100℃下保温3 h 后空冷,高铬铸铁硬度随奥氏体化温度的升高先上升后下降,在1000℃淬火时的硬度最高;在1000℃分别保温1、2、3和4 h后空冷,发现保温2 h铸铁的硬度达到峰值;对1000℃×2 h空冷的铸铁试样分别在250℃和450℃回火2 h,发现回火硬度均有小幅提高,但250℃回火的试样冲击性能显著提升,冲击吸收能量达到4．13 J。该叶片材料的最佳热处理工艺为1000℃×2 h空冷淬火＋250℃×2 h回火,用该工艺热外理叶片可获得弥散分布的M7 C3型碳化物＋二次碳化物＋回火马氏体基体及少量残留奥氏体组织,抗泥沙磨损能力提高了34．41％。     

Mar-M247合金双性能铸造整体叶盘热处理制度研究

研究了Mar-M247合金双性能整体叶盘的热处理工艺,具体为:1180℃×2h+1230℃×3h空冷+1100℃×4h空冷+870℃×20h空冷。     

Mar-M247合金双性能铸造整体叶盘热处理制度研究

研究了Mar-M247合金双性能整体叶盘的热处理工艺,具体为1 180℃×2 h+1 230℃×3 h空冷+1 100℃×4 h空冷+870℃×20 h空冷.     

热暴露对15CrMo钢微观组织的影响

在复杂的工况和恶劣环境(超温、火灾、爆炸、燃烧)下,15Cr Mo钢可能会过热。为了判断材料能否继续服役,通过模拟试验考察加热温度(500、600、700、750、850、900℃)、保温时间(1、2、5 h)和冷却方式(空冷、水冷)对15Cr Mo钢的微观组织及脱碳层深度的影响。结果表明,在500~900℃,随着加热温度的升高,15Cr Mo钢的总脱碳层深度逐渐增大。空冷处理后试样的总脱碳层深度比水冷处理的大。15Cr Mo钢总脱碳层深度与保温时间的平方根成线性关系。     

深冷处理对高Cr铸铁组织和耐磨性的影响

采用XRD、磁性法、硬度测量和磨损试验等方法研究了深冷处理对3Cr14Mn3MoV2高Cr白口铸铁显微组织和耐磨性的影响.结果表明,在去稳加空冷和去稳加深冷处理过程中,随着加热温度(900～1150℃)的升高,试样的硬度先升高后下降,并在1 000 ℃时达到最高值,深冷处理试样的硬度比深冷处理前明显提高,而且基本稳定在65 HRC左右;深冷处理使高Cr铸铁的残余奥氏体量大大下降,并且有二次碳化物析出,因此深冷处理使高Cr铸铁具有更高的耐磨性.     

热处理工艺对秸秆膨化机螺杆用Cr20高铬铸铁组织及耐磨性影响

对秸秆膨化机螺杆用Cr20高铬铸铁进行不同温度的淬火及回火处理,借助光学显微镜、扫描电镜、X射线衍射仪和磨损试验机等研究不同热处理温度和回火次数对Cr20高铬铸铁微观组织、硬度、韧性、耐磨性的影响。结果表明,采用990℃×1 h风冷淬火,配合250℃×1 h一次空冷回火和400℃×1 h二次空冷回火处理,Cr20基体组织二次碳化物析出量较多,马氏体含量高,材料耐磨性能好,耐磨性高于Cr15、Cr26高铬铸铁。     

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.     

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。     

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.     

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.