2.25Cr-1Mo-0.25V钢制加氢反应器用埋弧焊焊材试验研究

通过对2.25Cr-1Mo-0.25V钢用国产与进口埋弧自动焊焊材,用模拟件进行焊接试验,从焊接工艺性、化学成分、硬度、力学性能以及回火脆化等各项性能进行对比分析,结果表明,在相同的焊接参数和热处理条件下,国产焊材焊接工艺性良好,各项力学性能与进口同类焊材相当,能够满足2.25Cr-1Mo-0.25V钢焊接技术要求.     

T510L钢薄板的焊接工艺

通过对T510L钢的焊接性能分析,制定薄板的合理焊接工艺,并通过现场工艺性实验,成功地应用于产品。     

激光-MAG复合焊接技术在超高强钢上的应用分析

激光-电弧复合焊接技术具备焊接效率高、焊接变形小、焊接接头强度高、焊接工况适应性好、单面焊双面成形与柔性自动焊接等优点,已在高强钢、铝合金等结构件的焊接制造领域广泛应用。对激光-MAG复合焊接技术在超高强钢上的应用进行了分析,重点研究了其焊接工艺性、焊缝组织结构及焊接接头性能,解决了超高强钢与特种车辆车体构件的激光-MAG复合焊接工程化应用技术问题,达到了提高焊接接头性能、焊接质量及其稳定性,提高焊接效率,降低焊接变形的目的。     

Hardox 500耐磨钢板的焊接性及其应用

Hardox500钢板是一种细晶粒无碳化物马氏体和贝氏体耐磨钢板。对其焊接接头的性能、焊后组织的变化以及焊接工艺性进行了研究。结果表明：该钢板具有优良的焊接性,用500～600MPa级别的低合金钢焊条焊接取得了较好的效果,已在产品上成功应用。     

1Ni9钢在乙烯压缩机上的应用

阐述了-150℃工作的1Ni9低温用钢进行的焊接、热处理试验及焊接工艺评定等工作;并针对材料的焊接性能和产品特性设计了焊接叶轮的坡口型式及焊接工艺。完成了焊接力学性能试验、评价焊接材料,完成了工艺性试验、通过试验测定焊接收缩性能、制定焊接收缩量、评定-150℃焊接接头性能及焊接性能,确定产品叶轮焊接及焊后热处理工艺。     

某型号空调设备失效案例分析

针对空调铜管的泄漏失效问题,通过一个典型案例进行分析。通过打压试验、外观观察、低倍检查、扫描电镜观察、能谱分析等手段,分析出铜管的泄漏原因为不锈钢网和铜管焊接处的腐蚀导致,给出相应建议。     

神钢309 LCb不锈钢药芯焊丝单层堆焊工艺试验

采用日本神钢产CO2气体保护焊用309 LCb不锈钢药芯焊丝,在不同焊道搭接量下进行单层堆焊焊接工艺试验.结果表明,焊道搭接量2～3 mm可使单层堆焊过程稳定,焊接工艺性良好,堆焊层距表面3 mm范围内化学成分和铁素体数、金相组织、硬度值、晶间腐蚀、氢剥离以及各项理化性能满足要求.     

35CrMoA钢焊接性试验研究

针对军工专案产品中的重要部件焊接性差、结构复杂且刚性大的特点,研究探讨了其本体材料35CrMoA钢的焊接性,并在工况条件下进行了冷、热铁研抗裂性试验,从而为35CrMoA钢焊接工艺性试验研究提供了理论试验数据,为实际焊接生产提供了技术保证.     

奥氏体不锈钢316L焊接性能探讨

分析了钢的可焊性,制定了合理的焊接工艺,并进行了工艺性试验,验证了工艺规范可行,解决了316L钢的焊接性问题。     

制冷和空调行业用内螺纹焊接铜管生产工艺和技术优势探究

传统的空调制冷行业,主要运用的是无氟制冷剂。但是,目前传热效率过于低下,因此,需要借助内螺纹铜管替代原有换热元件,扩增热交换面积,从而提升热交换管换热系数。将高频焊接方法运用在生产内螺纹铜管的过程中,可以避免焊接质量问题和缺陷的发生,从而能够使空调更加的安全高效节能。     

铜/钢双金属复合管成形工艺研究

根据材料制备与零件制造一体化的原则,分析了粉末冶金覆层技术相关理论。试验研究出一套可行的铜/钢双金属复合管粉末冶金覆层技术方案,实现铜/钢双金属复合管制造的低成本和高性能。     

The effects of lubricant additives on wear and scuffing resistance of copper alloys under boundary conditions

The effects of lubricant additives on alloy composition and structure, and on the wear and scuffing resistance of copper alloys, were investigated. The copper alloys used were Sn bronze, Sn-Zn-Pb bronze, Al-Fe bronze, and Si-Mn brass. The base oil used was straight mineral oil. The additives used were dimer acid, phosphonate ester, sulphide olefine cotton-seed oil, ZDDP and n-dibutyl phosphite. The test results revealed that Si-Mn brass shows the highest resistance to wear and scuffing, and Sn-Zn-Pb the lowest. It also revealed that oiliness additives are superior in wear and tear scuffing resistance to EP additives, especially sulphur-containing additives. The authors also noted that copper alloys show good resistance to wear and scuffing when coupled with a polished steel surface.     

Electrode wear and material removal rate during EDM of aluminum and mild steel using copper and brass electrodes

In the present study an analysis has been done to evaluate the electrode wear along the cross-section of an electrode compared to the same along its length during EDM of aluminum and mild steel using copper and brass electrodes. In an overall performance comparison of copper and brass electrodes, we found that electrode wear increases with an increase in both current and voltage, but wear along the cross-section of the electrode is more compared to the same along its length. This is due to easier heat transfer along the length compared to the same along the cross-section of the electrode. It was also found that the wear ratio increases with an increase in current. That means, though a higher current causes more removal of work material and the electrode, comparatively more material is removed from the electrode. The highest wear ratio was found during machining of steel using a brass electrode. The low thermal conductivity of brass electrodes causes less heat loss, and its low melting point results in fast melting of the electrode material. At the same time, low thermal conductivity of steel results in poor heat absorption, and its high melting temperature causes poor removal of work material. These factors result in the highest wear ratio during machining of steel using a brass electrode. The highest material removal rate was observed during machining of aluminum using brass electrodes. Comparatively low thermal conductivity of brass as an electrode material does not allow the absorption of much heat energy, and most of the heat is utilized in the removal of material from aluminum workpiece at a low melting point. But during machining of steel using copper electrodes, a comparatively smaller quantity of heat is absorbed by the work material due to its low thermal conductivity. As a result material removal rate becomes very low.     

ESTIMATION OF RESIDUAL CONTACT PRESSURE IN HYDRAULICALLY EXPANDED CRA-LINED PIPE

The mechanically bonded CRA-lined pipe is developed to meet the need for corrosion-resistant alloy steel pipe. Residual contact pressure at the interface of lined pipe is important factor that governs the quality of lined pipe. A simplified theoretical method is presented to predict the residual contact pressure created by hydraulic pressure. The calculating equation related hydro-forming pressure to the residual contact pressure between two metal faces is derived. And the validation of the proposed equation is accomplished by comparing its result to those obtained by experimental investigation.     

尖晶石—硼玻璃陶瓷内衬钢管的研究

采用Fe2O3-Al Na2B4O7系铝热离心法制备了陶瓷内衬钢管。研究了Na2B47添加剂对自蔓延过程和陶瓷致密化的影响。在自蔓延过程中,作为稀释剂存在的Na2B4O7,降低燃烧温度和燃烧速度,增加了陶瓷中FeAl2O4含量;Na2B4O7添加剂形成了玻璃相,延长了陶瓷的熔融期,可显著改善陶瓷致密度和内表面光整度;Na2B4O7添加剂作为除锈剂,促使过渡金属与钢管纹。对陶瓷层孔隙率和组织结构进行了分析,结果表明：陶瓷层由大量铁铝尘晶石（FeAl2O4),少量刚玉（Al2O3）以及基体玻璃相组成,孔隙率为4．6％。     

耐磨铜合金的研究现状与发展趋势

机械设备高速度化及高性能化的发展要求耐磨铜合金具备更高的强度和更优异的耐磨性能.传统的铝青铜系、锰黄铜系和铅黄铜系等合金的性能虽已有所提升,但因受材料自身特性、加工工艺、环境保护等因素制约,其应用范围受限.从制备工艺、性能、应用领域等方面介绍了具备较高开发价值的Cu-Ni-Sn系、Cu-Al2O3系、Cu-Nb系、Cu...     

超声波金属焊接机气动回路及PLC控制系统的设计

对用于铜箔和铜管连续缝焊的超声波焊接机的气动和控制系统进行了设计分析。根据焊接工艺,拟定了气动回路,进行了气动元件的选择计算,确定了管道直径,验算了压力损失。拟定了PLC控制流程并对控制端口进行了分析,编写了控制程序,实现了铜箔和铜管的自动焊接。     

The effect of different contact materials on the fretting fatigue strength of an aluminium alloy

The fretting fatigue strength of Al-4Mg-0.7Mn in contact with pads of aluminium, copper, $\text{70}\text{30}$ brass, and 0.7 C steel has been determined. Copper and brass produced little reduction in fatigue strength because of the severe wear of the pads, The steel and aluminium pads produced reductions of 34% and 28% respectively. The effect of fretting on fatigue strength is explained in terms of the added shear stress arising from the frictional force between the pad and the specimen. Although the coefficient of friction is initially low it rises after 500–1000 cycles to approximately 1.0 and remains constant at this figure.     

自紧密封不锈钢衬里复合管液压胀合研究

研制开发了一种径向自紧密封式不锈钢衬里复合管液压胀合成形装置。讨论了复合管液压胀合成形过程的原理,并采用弹塑性理论分析了其在胀合成形过程中内管及外管的应力应变状态。利用变形协调条件,得出了胀合压力p_e与复合管内外管之间残余接触压力p_r~*的理论计算公式,并通过试验对公式进行了验证。结果表明该装置结构及其计算方法均可适于工程应用。     

Influence of electric current on the static friction of metal surfaces in air

The static coefficients of friction of aluminium, copper, brass and tin interfaces and aluminium mated with copper, brass and tin have been measured at light mechanical loading with the simultaneous passage of 50 Hz alternating current through the interface. When one surface was aluminium the friction was seen to decrease with increasing current. With brass/brass and copper/copper surfaces there was little dependence on current, while for tin/tin surfaces there was an increase in friction. These results indicate that the performance of aluminium power connectors which rely on frictional forces to maintain mechanical integrity may be in doubt during fault current conditions.