TC4钛合金与0Cr18Ni10Ti不锈钢真空热轧连接

利用真空热轧焊接的方法实现了镍作中间层材料的TC4钛合金与0Cr18Ni10Ti不锈钢板的连接.通过扫描电镜、能谱、X射线衍射等方法对连接界面的微观结构进行了描述,测试了Ni-TC4连接界面的金属间化合物层的成分,研究了焊接温度对焊接接头连接强度的影响规律.结果表明,金属间化合物层的厚度随着焊接温度的升高而增大,接头连接强度随之降低,当焊接温度为760℃、压缩率为20%、轧制速度为38 mm/s时焊接接头的抗拉强度达到最高值452.1MPa.拉伸试样断口均呈脆性断裂特征,XRD分析表明,在拉伸试样断口处存在多种Ni-Ti的金属间化合物.     

Mo-Cu合金与1Cr18Ni9Ti不锈钢真空钎焊接头的组织性能

采用Ag-Cu-Ti钎料,控制钎焊温度为910℃,保温时间为20 min,可以实现Mo-Cu合金与1Cr1 8Ni9Ti不锈钢的真空钎焊,接头抗剪强度为75 MPa.采用扫描电镜、能谱分析仪和显微硬度计对Mo-Cu/1 Cr18 Ni9Ti接头组织特征及性能进行分析.结果表明,钎焊接头靠近1Cr18Ni9Ti钢一侧,主要形成Ag-Cu共晶组织和少量的TiC相;靠近Mo-Cu合金一侧,Ag,Cu元素在合金与钎缝间相向扩散,共晶组织消失,以富铜相为主.钎缝的显微硬度明显低于Mo-Cu合金和1Cr18Ni9Ti不锈钢母材,无脆性化合物生成,剪切断口呈现剪切韧窝的形貌特征.     

5005铝合金与1Cr18Ni9Ti的真空钎焊分析

采用Al-Si-Mg钎料成功实现了5005铝合金与1Cr18Ni9Ti不锈钢的真空钎焊,借助扫描电镜、能谱分析仪和X射线衍射仪对焊后接头界面组织进行分析,同时对接头抗剪强度进行测试.结果表明,焊后接头界面结构从1Cr18Ni9Ti不锈钢侧到5005铝合金侧的界面组织依次为FeAl,FeAl₃,Fe_mAl_n+αAl.随着钎焊温度的升高或保温时间的延长,接头抗剪强度均呈现先升高后降低的变化趋势.当钎焊温度为580℃,保温时间为15 min时,接头抗剪强度达到最大值49 MPa.接头断裂形式受钎焊温度的影响,当钎焊温度较低时,接头断裂于铝合金侧氧化膜层及Fe_mAl_n+αAl反应层;温度升高至580℃时,接头断裂于Fe_mAl_n+αAl反应层中,接头抗剪强度最高.     

Microstructure and mechanical properties of Ti-6Al-4V/Ti-22Al-25Nb joint formed by diffusion bonding

Ti-6Al-4V (wt.%) and Ti-22Al-25Nb (at.%) were joined by diffusion bonding at 950 °C and 15 MPa for 100 min, and the microstructure and mechanical properties of the resulting joints were investigated. The composition of the diffusion layer is B2/discontinuous α/α₂ layer/necklace-shaped β+α′ layer, where the content of any element at a given point mainly depends on the distance of the point from the interface and the phase type at the point. The tensile strength of the joint is 894 MPa, which is almost the same as that of the Ti-22Al-25Nb base alloy. The fracture surfaces on both sides of the joint are composed of two main regions. One region displays a relatively flat surface and fractures along the bonding interface. The other is composed of a moderate number of irregularly-shaped cavities on the Ti-6Al-4V side and many irregularly-shaped bulges on the Ti-22Al-25Nb side. Both regions result from fracture along the boundaries between β+α′ layers and α_p grains or from the transcrystalline fracture of α_p grains.     

Study on wear resistant cast B-containing 1Cr18Ni9Ti stainless steel

The developed 1Cr18Ni9Ti austenitic stainless steel containing 1.63 wt.%B have been characterized by X-ray diffraction (XRD), electron probe microanalyzer (EPMA), optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and Vickers microhardness measurement. The microstructural evolution and property of high boron stainless steel after solution treatment at the temperature of 1050℃ are also investigated. The results show that the main compositions of borides are Fe, Cr and B, and with small amount of Ni, Mn and C elements. Silicon is insoluble in the borides. The hardness of borides is over 1,500 HV. It has been found that borides do not decompose during solution treatment, but part of borides dissolves into the matrix. The effect of increasing the solubility of boron element in the austenitic matrix favours the hardness enhancement by 8.54%. High boron stainless steel has excellent wear resistance in corrosive environment. Lifetime of transfer pipe made of high boron-containing stainless steel is 1.5-1.8 times longer than that of boron-free 1Cr18Ni9Ti stainless steel.     

High-temperature corrosion of Ti and Ti-6Al-4V alloy

Pure titanium and Ti-6Al-4V were exposed at 750°C in an H₂/H₂O/H₂S P_{O 2}10^–18 Pa and P_{S 2}10^–1 Pa), H₂/H₂O (P_{O 2}10^–18 Pa) and air environments for up to 240 hr. The corrosion kinetics, obtained by the discontinuous gravimetric method, showed that the sulfidation/oxidation kinetics were linear for Ti and linear-parabolic for Ti-6Al-4V in the H₂/H₂O/H₂S environment. Both materials obeyed parabolic rate laws in the H₂/H₂O atmosphere after a transient period, and linear-parabolic rate laws in air. After exposure to the H₂/H₂O/H₂S atmosphere, the titanium specimen displayed a double scale of TiO₂ with an intervening TiS₂ film between the double-layered scale of TiO₂ and the substrate. Ti-6Al-4V also contained a double layer of TiO₂ together with a stratum consisting of Al₂S₃, TiS₂ and vanadium sulfide at the junction of the inner TiO₂ layer and substrate. Some Al₂O₃ precipitated in the external portion of the outer TiO₂ layer. Following oxidation in the low-P_{O 2} atmosphere a double-layered oxide of TiO₂ scale formed on both Ti and Ti-6Al-4V. The scale on Ti-6Al-4V also contained an -Al₂O₃ film situated between the outer and inner (TiO₂) layers. For both materials, multilayered-scale formation characterized air oxidation. In detail a multilayered oxide scale of TiO₂ formed on the air-oxidized Ti, while a multilayered oxide scale with alternating layers of Al₂O₃/TiO₂ developed on Ti-6Al-4V oxidized in air.     

Ti基钎料真空钎焊Ti-6Al-4V

在温度1223K、时间1－30min钎焊参数条件下，应用Ti基钎料对Ti-6Al-4V进行了真空钎焊。结果表明，接头强度较高，因钎焊温度较低母材基本上保留了原始组织。同时表明Ti-Zr-Cu钎料大幅度增加w(Cu)易造成钎缝中心区域生成连续分布的Ti2Cu TiCu,严重影响接头强度。     

1Cr18Ni9Ti与1Cr13不锈钢的焊接试验

通过钨极氩弧焊方法,对 1Cr18Ni9Ti 与 1Cr13 实施焊接.采用光学显微镜、扫描电镜对 1Cr13 马氏体型与 1Cr18Ni9Ti 奥氏体型不锈钢焊接接头进行金相组织、断口形貌观察及分析;利用显微硬度计、电子万能拉伸机测量焊接接头的力学性能;并通过海水模拟溶液浸泡试验,测量焊接接头极化曲线和交流阻抗谱.结果表明,通过手工钨极氩弧焊,采用直流正接接法,在合适的工艺下(焊接电流为 80 A,焊接速度为 110 mm/min),能够获得外观平整、组织均匀,力学性能与电化学性能符合要求的焊接接头.

Abstract：

The stainless steels of 1Cr18Ni9Ti and 1Cr13 were welded through deterministic craft by tungsten inert-gas (TIG) welding. The microstructure and fracture pattern of weld joints of 1Cr13martensite and 1Cr18Ni9Ti austenite stainless steels were observed and analyzed by means of LOM and SEM, the mechanical properties of the weld joints were measured with micro-hardness tester and electronic universal stretcher, and the polarization curves and AC impedance spectroscopy of weld joints were tested by seawater immersion test of simulation solution. The results show that adopting manual TIG welding through electrode negative to direct current soldering machine to weld 1Cr18Ni9Ti austenite stainless steel and 1Cr13 martensite stainless steel is feasible; under suitable process (welding current is 80 A, welding speed is 110 mm/min), weld joints can obtain good appearance and uniform structure; mechanical properties and galvano-chemistry properties can meet use requirements.     

6063铝合金／Ag／Ni／1Cr18Ni9Ti共晶反应钎焊研究

研究采用Ni-Ag复合镀层,在特定的工艺参数条件下,对6063铝合金与1Cr18Ni9Ti进行了共晶反应钎焊试验,初步分析探讨了工艺参数对钎缝微观组织结构反形态的影响和Ni层的阻隔作用.对钎缝的界面作扫描电镜和能谱分析发现,镀层与母材等各界面连接紧密,特别是钎缝与母材之间没有生成脆性Al-Fe金属间化合物.结果表明:在钎焊温度580℃,共晶反应钎焊6063铝合金1Cr18Ni9Ti,保温5 min,钎缝成形较好;面心立方结构Ni/Ag电刷镀层能有效地阻挡Al,Fe等原子扩散.     

Effect of Hydrogen on Diffusion Bonding Behavior and Mechanism of Ti-6Al-4V alloy

研究了置氢Ti-6AL-4V合金在800~860℃温度范围内气压扩散连接行为与机理。在840℃对置氢0.11%(质量分数,下同)的纯钛和Ti-6AL-4V合金进行了扩散连接。应用光学显微镜(OM)、扫描电子显微镜(SEM)和电子探针显微分析仪(EPMA)研究了氢对扩散连接接头焊合率及元素扩散行为的影响。结果表明:氢能够显著提高扩散连接接头的焊合率(置氢0.11%在840℃的焊合率大于98%);氢含量为0.11%的Ti-6Al-4V合金扩散连接后仍为等轴组织,而高氢含量(0.32%~0.48%H)Ti-6Al-4V合金扩散连接后组织转变为粗大的魏氏组织;氢对扩散连接行为的改善作用主要是由于氢的弱键效应及其对元素扩散系数的提高;相对于未置氢Ti-6Al-4V合金,0.11%的氢能够将Al和V元素的扩散系数提高一个数量级,并使扩散连接温度降低了40℃。     

ZG1Cr18Ni9奥氏体不锈钢的渗硼

对ZG1Cr18Ni9奥氏体不锈钢进行了渗硼处理,渗硼剂采用含双活化剂(氟硼酸钾和氯化铵)的粉末渗硼剂:碳化硼+碳粉+碳化硅+氟硼酸钾+氯化铵,渗硼温度为950 ℃,渗硼时间为7 h.在金相显微镜下观察渗层组织致密,齿型平坦,并测得渗层的厚度为38～42 μm;经X射线衍射分析以及扫描电镜观察表明,渗层主要由FeB相组成,在过渡区有明显的增铬现象,说明硼化物层有一定的排铬作用.利用显微硬度计测得渗后形成的硼化物层的硬度可达2000 HV0.1.沿硼化物-过渡区-基体方向,硬度值呈逐渐下降趋势.渗层的脆性较小,脆性级别为2级.ZG1Cr18Ni9奥氏体不锈钢通过含双催渗剂的渗硼剂渗硼,组织均匀且与基体结合紧密,硬度明显提高.     

Fe-Cr-2Al-Si阻尼合金与1Cr18Ni9Ti不锈钢的钨极氩弧焊接

采用钨极氩弧焊（GTAW）和奥氏体不锈钢焊丝LNT309LSi作为填充金属,研究了Fe-Cr-2Al-Si阻尼合金和1Cr18Ni9Ti不锈钢的焊接工艺和焊接质量。借助金相显微镜分析了焊缝组织特征,采用电子探析分析了焊缝成分。按照国家标准研究了焊接接头的硬度、拉伸性能和弯曲性能。结果表明,用奥低不锈钢焊丝焊接Fe-Cr-2Al-Si阻尼合金和1Cr18Ni9Ti不锈钢,可获得理想的奥氏体＋少量的铁素体＋马氏体的焊缝组织,焊缝的抗拉强度和抗弯性能均高于阻尼合金。所采用的焊接方法、焊接工艺和焊丝能满足这两种钢的焊接要求,焊接质量可靠。     

Ti-6Al-4V合金热加工用无铅玻璃-陶瓷抗氧化涂层研究

制备了一种用于防止Ti-6Al-4V钛合金加热时表面氧化的无铅玻璃-陶瓷涂层材料,并对其相组成及有涂层钛合金氧化层进行了研究。结果表明,加热前涂层主要为玻璃相,加热后有结晶相生成,有利于从钛合金表面除去涂层;有涂层钛合金表面氧化层厚度小。可见,无铅环保型涂层能在500~1000 ℃温度范围内给Ti-6Al-4V合金提供良好的抗氧化保护。     

Study of diffusion bonding of Ti-6Al-4V and ZQSn10-10 with metal interlayer

The diffusion bonding was carried out to join Ti alloy (Ti-6Al-4V) and tin-bronze (ZQSn10-10) with Ni and Ni Cu interlayer. The microstructures of the diffusion bonded joints were analyzed by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The results show that when the interlayer is Ni or Ni Cu transition metals both could effectively prevent the diffusion between Ti and Cu and avoid the formation of the Cu-Ti intermetallic compounds (Cu3Ti, CuTi etc.). But the Ni-Ti intermetallic compounds (NiTi, Ni3Ti) are formed on the Ti-6Al-4V/Ni interface. When the interlayer is Ni, the optimum bonding parameters are 830℃/10 MPa/30min. And when the interlayer is Ni Cu, the optimum bonding parameters are 850℃/10MPa/20min. With the optimum bonding parameters, the tensile strength of the joints with Ni and Ni Cu interlayer both are 155.8MPa, which is 65 percent of the strength of ZQSn10-10 base metal.     

钛合金与不锈钢的纳米扩散焊接工艺探索

采用纳米镍粉为中间层对TA17钛合金与1Cr18Ni9Ti进行了扩散焊接试验。通过金相分析、能谱分析、X射线衍射等手段对焊接接头进行了较详细的分析。结果表明,纳米镍粉成功地阻止了钛合金与不锈钢的互扩散,抑制了TiFe,TiFe2等脆性相的形成,在接头形成了具有一定塑性的Ni-Ti型金属间化合物,但由于纳米镍粉中间层不致密,从而导致接头强度较低。     

Impact pressuring diffusion bonding of TA17 to 0Cr18Ni9Ti

Impact pressuring diffusion bonding tests were carried out to produce joint between TA17 titanium alloy and 0Cr18Ni9Ti stainless steel. The reaction products and microstructure near the bonding interface were analyzed. The diffusion of Fe, Cr, Ni and Ti in the bond was revealed by energy dispersive spectroscopy. A number of phases, such as β-Ti, Fe2Ti and σ phases were identified by X-ray diffraction. It was concluded that the bonded joint broke in the region somewhere between Fe-Ti intermetallics and β-Ti during tensile loading. The relationship between bonding parameters and tensile strength of the joint was also determined experimentally, and the optimum time of bonding was only 220 s with 293 MPa joint strength.     

钛合金与不锈钢的相变超塑性扩散焊工艺

用相变超塑性扩散焊法实现了钛合金TA17与不锈钢0Cr18Ni9Ti之间的连接.研究了工艺参数对接头强度的影响,得到试验条件下钛合金与不锈钢焊接的优化工艺参数为循环上限温度890℃, 循环下限温度800℃, 循环次数10, 焊接压力5MPa, 循环加热速度30℃/s.在优化的工艺条件下,接头强度达到307MPa,而焊接时间仅为160s.对拉伸断口进行了扫描电镜观察、能谱分析和X射线衍射分析,发现断裂沿FeTi和β-Ti层之间的某一个位置发生,FeTi金属间化合物层是接头的最薄弱环节.对接头进行了能谱分析,结合Fe-Cr-Ti三元相图发现,钛合金与不锈钢之间的反应区内依次形成了σ、Fe2Ti、FeTi和β-Ti层.     

1Cr18Ni9Ti奥氏体不锈钢冷变形与再结晶组织及性能

研究了1Cr18Ni9Ti奥氏体不锈钢加工硬化时组织的演变过程及其对性能的影响。结果表明，冷变形可提高钢的各种强度性能指标，尤其大大改善疲劳性能。经60％变形后，钢的疲劳强度提高了65％左右。随着加热保温时再结晶过程的进行，钢的强度下降而塑性逐步恢复。     

处理温度对1Crl8Ni9Ti钢脉冲直流等离子渗氮的影响

利用脉冲直流辉光等离子技术，在不同的温度下对1Cr18Ni9Ti奥氏体不锈钢进行了渗氮处理。利用光学显微镜、显微硬度计、XRD以及电化学工作站对渗氮层进行了分析。结果表明，处理温度显著影响1Cr18Ni9Ti钢渗氮层的结构与性能。处理温度≤440℃时，渗层为纯S相结构；处理温度在460～540℃之间时，为S相＋CrN＋Fe4N的混合组织；处理温度≥560℃时，为CrN＋Fe4N的化合物层。可在较宽的温度范围内对该钢进行脉冲直流等离子渗氮，获得表面硬度高于基底5～6倍的渗氮层。渗氮层的厚度随处理温度的升高而增加，而抗腐蚀性能随着处理温度的升高呈下降趋势。