镍焊补在机床导轨拉伤修复中的应用

镍焊补在机床导轨拉伤修复中的应用大连化学工业公司机械厂杜立东，赵宝林，郭永强我们在Ｔ６１１卧式镗床大修理过程中，发现床身导轨而拉伤严重，拉伤面积横向宽１１０ｍｍ，长１５００ｍｍ，成片分布，沟深为０．１～１．５ｍｍ，宽窄在０．０５～３ｍｍ不等。如此严重...

镍焊膏的制备

以镍基合金为原料,高纯氮气为雾化气体,在合适的熔体温度、熔体漏速和雾化气体压力下,可制备出球形度好、氧含量0.014%、粒度约70μm的镍钎料粉末.以工业白油和聚合物为成膏体制备的镍焊膏,其焊接质量达到了国标要求.

稀土元素对镍基喷焊合金层摩擦表面形成氧化物膜的影响

稀土元素能够有效地改善镍基喷焊合金层的组织，提高其耐磨性和承载能力．为了弄清稀土元素在镍基喷焊合金层中的作用机理，利用Ｘ射线光电子能谱仪、俄歇电子能谱仪和二次离子质谱仪等现代分析设备，就稀土元素对镍基喷焊合金层摩擦表面形成氧化物膜的影响进行了试验研究与分析．结果表明，添加稀土元素能够明显增大喷焊合金层摩擦表面氧化物膜的厚度，并在氧化物膜与基体之间产生富集，这对提高喷焊合金层与基体的结合强度。

国产镍基合金带极电渣堆焊在三相分离器制造中的应用研究

针对为某气田研究设计并制造的高含硫天然气三相分离器设备中的抗腐蚀性能要求,需在设备壳体内壁堆焊Inconel 625镍基合金,确定采用国产镍基合金带极电渣堆焊技术进行内壁堆焊的工艺方案,并进行了焊接工艺评定。评定结果表明,国产镍基合金钢带堆焊工艺性良好,各项性能指标均满足相关标准要求及三相分离器的制造技术要求,并完成了该产品的制造。

镍基合金喷焊层焊接时组织变化及裂纹敏感性研究

1.前言 传统的涂层防护方法是有机涂层防护,但是有机涂层存在易老化、不耐高温等缺点.利用火焰喷熔玻璃釉料在管道内外壁上制备玻璃涂层的防腐工艺是目前一项新技术,防腐效果相当好.然而,由于玻璃釉层脆性大、塑韧性差,焊缝处的玻璃釉层会在焊接热循环的作用下出现脱落、开裂等缺陷,从而失去了防护作用.石油大学(华东)曾提出"一种取代金属焊后防腐处理的焊接方法"(专利申请号97106107).该方法采用THL焊条焊接带镍基合金喷焊层的碳钢管道,焊接时,THL焊缝金属和喷焊层连成一体,构成对整个碳钢管道的防护层.由于焊接热循环的作用,喷焊层组织性能会发生变化,尤其是在近缝区可能产生裂纹,喷焊层与碳钢基体剥离,这将对焊接接头的使用构成极大的威胁.为此,我们采用模拟实际情况的试验,研究了焊接热循环对喷焊层组织性能的影响,为解决焊接接头的防护问题打下了基础.

国产镍基埋弧焊焊接材料在甲醇合成装置中的应用

采用国产镍基埋弧焊丝与焊剂HS600/SJ608,对14Cr1MoR与镍基HS600之间的异种钢焊接接头进行了力学性能和显微组织变化分析,并与甲醇合成装置中进出口热交换器的相关应用数据进行对比分析。分析结果表明,镍基埋弧焊焊接接头的弯曲性能符合要求,母材区的硬度值为158HV,焊缝区的硬度最高为200HV,热影响区的硬度比母材区的硬度稍高,为168HV;热影响区的晶粒有一定的长大,并且珠光体相有所减少;焊缝区组织主要是针状γ相,γ相的形成增加了焊缝区的硬度。采用HS600/SJ608镍基埋弧焊丝与焊剂可以实现对大厚度板材14Cr1MoR的焊接,焊接接头的拉伸强度可以达到560MPa,且在母材区断裂,满足实际应用要求,可以替代进口焊接材料ERNiCr-3。

大型镍衬里容器

该文介绍了镍衬里容器的制造过程、制造标准、质量控制要点和检验内容,并重点介绍了纯镍与纯镍、纯镍与异种钢的焊接工艺:采用TiG,正确选用ERNiCr-3、WelTiGNi-1、N_6焊丝能获得质量优良的焊缝。文章还对镍衬里容器的制造和使用的可行性作了分析。

非典型的焊盘原因导致的焊接不良案例分析

本文通过对一例非典型原因导致的焊盘可焊性不良而引起的焊接不良案例的分析，介绍了焊接失效的分析过程。对于润湿不良且无明显的氧化、污染或被腐蚀的特征的非典型焊盘，业界一直找不到真正的原因。而本文则通过引入光电子能谱的表面分析手段，对润湿不良的焊盘的表面化学物质组成及其深度分布进行了分析，结果发现镍镀层中镍的扩散至金表面导致了焊盘可焊性的急剧下降，最终揭示了导致使用该焊盘进行焊接而引起的焊接不良的主要原因，为下一步避免或控制类似问题提供了改进的依据。

冷轧和退火对纯镍拼焊接头组织和力学性能的影响

对纯镍板拼焊接头进行冷轧,然后进行800~1100℃退火,通过对比分析,研究了冷轧和退火工艺对纯镍板材的组织和力学性能的影响。结果表明,经过75%变形量的冷轧加工后,拼焊接头的晶粒破碎,微观组织沿轧制方向呈线性纤维状,其抗拉强度约611 MPa,伸长率约5.6%。在800℃退火时,显微组织发生部分再结晶,但仍然存在大量拉长的线性纤维组织,抗拉强度为387.9 MPa,伸长率为20.4%;在900℃退火时,大部分线性纤维组织发生再结晶,抗拉强度为363.5 MPa,伸长率为23.7%;1000℃退火时,冷轧形成的线性纤维组织完全消失,微观组织发生完全再结晶,抗拉强度为357.5 MPa,伸长率为32.3%;在1100℃退火时,与1000℃退火时相比,微观组织变化不明显,力学性能也无明显变化,抗拉强度为355.3 MPa,伸长率为30.9%。由力学性能和微观组织综合比较可知,1000℃为最佳的中间退火温度。

TA1纯钛表面镍基喷焊层的组织和磨损性能

利用等离子喷焊技术在TA1纯钛表面制备了镍基耐磨喷焊层,研究了喷焊层结构、显微组织和显微硬度以及摩擦磨损性能。结果表明:喷焊层由过渡层和强化层组成,焊层与基体间形成了基于原子扩散的冶金结合界面及以树枝晶为主的过渡层。喷焊层的组织主要由γ-Ni固溶体,γ-Ni(Ti)固溶体以及TiC、Cr_7C_3、Ni_3B和TiB_2等硬质相组成。强化层为韧Ni基体+硬质相耐磨组织,硬度(HV_(0.5))在8300~9070 MPa之间,较基体高出7000 MPa。喷焊层主要合金元素的扩散、显微组织变化及显微硬度沿层深方向的分布具有连续性和渐变性。与基材TA1对比试验表明,喷焊镍基合金后摩擦系数降低,耐磨性明显提高,喷焊层磨损面呈轻微的磨粒磨损特征。

喷焊镍基合金液力反馈抽油泵柱塞失效分析

用电子显微分析(SEM)和X射线能谱分析(XRD)研究喷焊镍基自熔合金柱塞失效的原因。结果表明,喷焊柱塞镍基合金涂层在井下硫-氧-碳混合气氛的工况环境中发生硫化和氧化腐蚀反应,生成以CrS,Cr_3S_4,Ni_3S_2,FeS和NiO等多元复合且疏松、可剥离的金属硫化物和氧化物垢盐类组织相,使柱塞直径尺寸胀大,配合超差,且涂层表面硬度明显下降。通过分析喷焊镍基合金涂层的腐蚀机理,提出加入可细化组织晶粒并且具有优异的抗硫化能力的合金元素Mo和Nb,明显提高其抗硫化能力和综合使用性能。

Parameter optimization for tungsten carbide/Ni-based composite coating deposited by plasma transferred arc hardfacing

Ni-based composite coatings with a high content of tungsten carbides(Stelcar65composite coatings)were synthesized by plasma transferred arc(PTA)hardfacing.The welding parameters of Stelcar65composite coatings were optimized by orthogonal tests.The PTA welding parameters including welding current,powder feed rate and welding speed have significant influence on the tungsten carbide degradation.The values for the optimum welding current,powder feed rate and welding speed were determined to be100A,25g/min and40mm/min,respectively.The produced WC/Ni-based composite coatings were crack-and degradation-free.The microstructure of deposited layers,as well as the microstructure and microhardness of the optimal coating were further analyzed.

Au线改Cu线的新发展及可靠性研究

Au线作为内引线一直占据着键合的主导地位,而由于Cu线具有优良的电性能和价格优势,随着键合技术的发展,以Cu丝代替Au丝作为键合用内引线已经成为现在的主要趋势。介绍了Cu线相对于Au线的优势、存在的可靠性问题,并对Cu引线键合新的发展趋势、如何进行可靠性验证等问题进行了研究。

两种镍基合金喷焊层的相分布与热疲劳性能

利用扫描电子显微镜、X射线衍射仪及透射电子显微镜观察分析了含Cu和Mo(Ni-A)、不含Cu和Mo(Ni-B)两种镍基合金喷焊层样品的组织、相分布和成分分布,分别测定了基体部位、热影响区、结合区及涂层内的显微硬度.利用高频加热炉对两种喷焊层进行了热疲劳实验,对经热疲劳实验后喷焊层微观组织进行了观察,分析了喷焊层内的相分布和成分分布状态,探讨了热疲劳裂纹产生和扩展的过程及规律.结果表明:两种喷焊层内均有针状富Cr第二相弥散分布,具有较好的热疲劳性能.Ni-A样品喷焊层可以分成两个区域:在靠近基体的区域均匀地分布着块状富Cr第二相;在离表层200μm左右的区域内分布有针状富Cr第二相,体积比块状富Cr第二相小几十倍.Ni-B样品喷焊层内只有针状富Cr第二相,在整个喷焊层内均匀分布.Ni-A样品喷焊层由于过渡区域的存在,具有比Ni-B样品喷焊层更好的热疲劳性能.热疲劳实验前后样品的EDS分析结果表明两种喷焊层内的各相有较好的热稳定性.

Microstructure and mechanical characterization of Incoloy 825 Ni-based alloy welded to 2507 super duplex stainless steel through dissimilar friction stir welding

The feasibility of dissimilar friction stir welding(FSW)between the SAF 2507 super duplex stainless steel and the Incoloy825 Ni-based superalloy was evaluated.The microstructure and mechanical behavior of the weldments were examined too.The results showed that the alloys were successfully welded together by positioning the SAF 2507 on the advancing side.The nuggets displayed higher hardness than the base metals,due to the occurrence of dynamic recrystallization and the subsequent refinement of the microstructures.The welded sample obtained the similar strength to the Incoloy 825 parent metal,showing the ductile fracture mode after the tensile tests by SEM.Moreover,the weld zone(31 J)exhibited higher and lower toughness than the Incoloy 825(23 J)and SAF 2507(42 J)parent metals,respectively.Based on the obtained results,the FSW method could be recommended to weld the super duplex stainless steel/Ni-based superalloy joints.

Interfacial reactions between Sn-2.5Ag-2.0Ni solder and electroless Ni(P) deposited on SiC_p/Al composites

A novel Sn-2.5Ag-2.0Ni alloy was used for soldering SiCp/Al composites substrate deposited with electroless Ni(5%P) (mass fraction)and Ni(10%P)(mass fraction)layers.It is observed that variation of P contents in the electroless Ni(P)layer results in different types of microstructures of SnAgNi/Ni(P)solder joint.The morphology of Ni3Sn4 intermetallic compounds(IMCs)formed between the solder and Ni(10%P)layer is observed to be needle-like and this shape provides high speed diffusion channels for Ni to diffuse into solder that culminates in high growth rate of Ni3Sn4.The diffusion of Ni into solder furthermore results in the formation of Kirkendall voids at the interface of Ni(P)layer and SiCp/Al composites substrate.It is observed that solder reliability is degraded by the formation of Ni2SnP,P rich Ni layer and Kirkendall voids.The compact Ni3Sn4 IMC layer in Ni(5%P)solder joint prevents Ni element from diffusing into solder,resulting in a low growth rate of Ni3Sn4 layer.Meanwhile,the formation of Ni2SnP that significantly affects the reliability of solder joints is suppressed by the low P content Ni(5%P)layer.Thus,shear strength of Ni(5%P) solder joint is concluded to be higher than that of Ni(10%P)solder joint.Growth of Ni3Sn4 IMC layer and formation of crack are accounted to be the major sources of the failure of Ni(5%P)solder joint.

An investigation on electrochemical performances of as-cast and annealed La_(0.8)Mg_(0.2)Ni_(3.3)Co_(0.2)Si_x(x=0-0.2)alloy electrodes for Ni/MH battery application

The La-Mg-Ni-based A2B7-type La0.5Mg0.2Ni3.3Co0.2Six （x=0-0.2） electrode alloys were prepared by casting and annealing. The influences of the additional silicon and the annealing treatment on the structure and electrochemical performances of the alloys were investigated systemically. Both of the analyses of XRD and SEM reveal that the as-cast and annealed alloys are of a multiphase structure, involving two main phases （La, Mg）2Ni7 and LaNi5 as well as one minor phase LaNi3. The addition of Si and annealing treatment bring on an evident change in the phase abundances and cell parameters of （La, Mg）2Ni7 and LaNi5 phase for the alloy without altering its phase structure. The phase abundances decrease from 74.3% （x=0） to 57.8% （x=0.2） for the （La, Mg）2Ni7 phase, and those of LaNi5 phase increase from 20.2% （x^0） to 37.3% （x=0.2）. As for the electrochemical measurements, adding Si and performing annealing treatment have engendered obvious impacts. The cycle stability of the alloys is improved dramatically, being enhanced from 80.3% to 93.7% for the as-annealed （950 ℃） alloys with Si content increasing from 0 to 0.2. However, the discharge capacity is reduced by adding Si, from 399.4 to 345.3 mA.h/g as the Si content increases from 0 to 0.2. Furthermore, such addition makes the electrochemical kinetic properties of the alloy electrodes first increase and then decrease. Also, it is found that the overall electrochemical properties of the alloys first augment and then fall with the annealing temperature rising.

Transformation mechanism of secondary phase and its effect on intergranular corrosion in laser wire filling welding Ni-based alloy/304 stainless steel

To clarify the transformation mechanism of secondary phase and the mechanism of intergranular corrosion in laser welding Ni-based alloy (Hastelloy C-276)/304 stainless steel with filler wire,the secondary phase was analyzed by electron probe micro-analysis (EPMA) and transmission electron microscopy (TEM).The evaluation of intergranular corrosion resistance of the welded joints was conducted by double-loop electrochemical potentiokinetic reactivation(DL-EPR) method,and at the same time the chemical compositions of the corrosion surface were analyzed by energy-dispersive spectrometry (EDS).The results show that p phase has complete coherence relationship withμphase,and the coherent relationship is described as[001]p//■and[430]p//[0001]μ.Theμphase is rapidly transformed from p phase,which is the inhomogeneous phase transformation.The transformation of secondary phase will increase the susceptibility to intergranular corrosion.Therefore,the transformation of secondary phase should be avoided in the welding process.

Influence of rotational speed in friction surfacing of nickel-aluminide reinforced aluminum matrix composite on commercially pure aluminum

The effect of rotational speed in the friction surfacing of nickel-aluminide reinforced Al-Zn-Mg-Cu alloy matrix composite on commercially pure aluminum was investigated. The nickel-aluminide reinforcement was fabricated by in-situ methods based on adding nickel powders to Al-Zn-Mg-Cu alloy melt during the semi-solid casting process.The findings showed that an increase in the rotational speed from 600 to 1000 r/min raised the coating efficiency from 65% to 76%. Besides, there was no significant difference between coating efficiencies in the coating with and without nickel-aluminide. The outcomes showed that if the coating was applied at a rotational speed of 1000 r/min, a traverse speed of 100 mm/min, and an axial feeding rate of 125 mm/min, the hardness and shear strength of the substrate increased by up to 225% and 195%, respectively. But the wear rate of the substrate dropped by 75%. Although the hardness of the coating containing nickel-aluminide increases by up to 32% compared to the coating without nickel-aluminide, nickel-aluminide does not affect the thermal stability of the coating.