共查询到20条相似文献,搜索用时 187 毫秒
1.
2.
45钢激光熔覆镍基合金组织及性能研究 总被引:1,自引:0,他引:1
采用横流CO,激光器在45钢表面激光熔覆了一层镍基合金涂层,研究了激光加工工艺对熔覆层组织、性能的影响。结果表明:熔覆层宏观质量良好;熔覆层与基体形成了良好的冶金结合;熔覆层组织均匀致密并呈现出垂直于界面的定向凝固特征,从结合区到表面依次为平面晶、胞状晶、粗大枝晶、细小枝晶等;熔覆层显微硬度与绝对比能量有关,其值为12时有最大硬度,可达610.6HV,为基体硬度的4倍。综合考虑各影响因素并进行正交分析得出结论:送粉率7.1g/min、扫描速度2.5mm/s、激光功率3000W时为最佳工艺参数。 相似文献
3.
钨极氩弧焊是现代工业制造中一种十分重要的焊接方式,为改善不锈钢薄板的焊接质量,进行了不同的钨级形状氩弧焊试验研究。试验结果表明,平顶锥端头钨极焊接工艺容易实现单面焊双面成形,可有效减小焊接热影响区,保证良好的力学性能和外观质量。 相似文献
4.
5.
研究了直流钨极氩弧焊(直流TIG)、脉冲钨极氩弧焊(脉冲TIG)和激光焊接3种不同焊接工艺对TA18钛合金焊接接头宏观形貌、显微组织和力学性能的影响。结果表明,与直流TIG焊接工艺相比,脉冲TIG焊接工艺的高频脉冲促使电弧能量集中,整体的焊接热输入减小,焊缝宽度降低;激光焊接工艺可显著降低焊接接头宽度,与直流TIG焊接工艺相比,焊接接头宽度减少约69.5%。TA18钛合金激光焊接接头显微组织主要为网篮状排列的针状马氏体α′相及少量块状相变α相,且针状马氏体α′相更加细小。此外,激光焊接接头具有更高的显微硬度,但弯曲性能相对较低。 相似文献
6.
介绍了CDQ锅炉管手工TIG(钨极氩弧焊)焊接工艺要求以及焊接参数对焊缝质量的影响,阐述了焊接规范以及现场焊接操作中应注意的事项,依焊缝质量的评定结果提出了相关建议。 相似文献
7.
核能已经逐渐取代化石能源成为新一代能源,作为重要构件的高温气冷堆中间换热器得到了广泛关注。由于GH3128合金具有较好的焊接性、较高的高温抗氧化性能和组织稳定性,有望成为超高温气冷堆中间换热器的候选材料,但基于换热器结构复杂性以及密封性的要求,焊接是其生产和制造的关键成形手段。采用脉冲钨极氩弧焊(GTAW)对GH3128合金2 mm板材进行对接焊,研究了热处理对焊接焊接接头显微组织以及应力的影响。结果表明,在优化焊接工艺参数下,固溶态板材接头表现出最高的强塑性,室温及高温拉伸断裂位置均为母材。由于热轧态与固溶态板材接头热影响区在焊接过程中产生残余应力,导致该区硬化,在高温变形过程中残余应力诱发热影响区μ相析出,对接头持久、蠕变性能造成不利影响。焊后热处理消除了接头热影响区的残余应力,减少了持久、蠕变过程中μ相的析出,接头持久寿命得以改善。在1 200 ℃下,残余应力可为焊后热处理过程中静态再结晶提供激活能,接头热影响区发生再结晶,硬度下降,接头塑性变形能力不协调,导致室温拉伸与950 ℃拉伸断裂位置均为焊接接头。对固溶态板材试样进行不同的焊后热处理,EBSD扫描结果分析发现,接头经过1 100 ℃×10 min热处理后,残余应力明显消失,温度升高至1 140 ℃后,热影响区开始发生再结晶。 相似文献
8.
《稀有金属》2017,(12)
为了研究球墨铸铁QT600-3表面激光熔覆钴基合金的组织和性能,本试验采用预置送粉法,利用6 kW CO_2激光器将粒度为46~106μm的CoCrW合金粉末激光熔覆到QT600-3基材表面,激光熔覆工艺参数为:激光功率P=3.0 kW、扫描速度V=350 mm·min~(-1)、光斑直径2 mm、搭接率1.5,三道次熔覆,熔覆层厚度约为3 mm,在熔覆过程中采用热量补偿方法对试样温度场进行调控。通过Olympus金相显微镜(OM)、Zeiss-Sigma扫描电镜(SEM)、X'Pert MPD Pro型X射线衍射仪(XRD)、MHV2000数显显微硬度计,分析了熔覆层横截面的显微组织、物相及硬度的变化规律。结果表明:熔覆层表面成形良好,无裂纹、气孔等缺陷;熔覆层分为熔化区、结合区和热影响区,熔覆层与基体冶金结合良好,主要由γ-Co(面心立方)过饱和固溶体以及碳化物CoC_x,Cr_7C_3等组成;熔化区由表层的树枝晶和内部的胞状晶组成,在热影响区发生了组织转变,形成了马氏体并且球状石墨部分溶解,直径变小。熔覆层硬度随着与球墨铸铁基体表面距离增加,呈现先快速增大,后平缓增加,最后在表层区域又快速增大,熔覆层的最高硬度达到HV0.21077,较球墨铸铁基体的硬度提高了4倍以上。 相似文献
9.
采用真空熔结工艺制备了TiC钢结硬质合金/Q235钢复合板,研究了复合板界面显微组织和力学性能。结果表明:钢结硬质合金与Q235钢基体之间形成了一定宽度的互溶区,互溶区宽度主要取决于熔结温度和熔结时间。Mn、Ni、Mo元素由钢结硬质合金经互溶区向基体中扩散,Fe元素由基体通过互溶区向钢结硬质合金扩散。互溶区是材料显微组织、化学成分及显微硬度变化的过渡区。复合板界面剪切强度为176~245 MPa,表明钢结硬质合金与Q235钢基体之间形成冶金结合。 相似文献
10.
针对冶金辊材的表面强化和再制造需求,采用激光熔覆技术在辊芯常用材料球墨铸铁表面制备了10V高速钢熔覆层,研究了半导体直接输出激光器的工艺对熔覆过程、熔覆层组织结构与性能等的影响.结果表明:半导体激光器能够显著提高熔覆效率,避免了脉冲激光熔覆时的开裂现象;获得的熔覆层连续平整、无裂纹气孔等宏观缺陷,与球墨铸铁基体呈冶金结合状态.熔覆层显微组织特征为片层状、块状、球形颗粒状等多种形貌的快速凝固组织,由α-Fe,VC,γ-Fe,Cr23C6和Fe V等组成.熔覆层内合金元素的成分宏观均匀分布,微区有V等偏析.熔覆层显微硬度达700 HV0. 1,是基体硬度320HV0. 1的2. 18倍.在优化的工艺条件下,熔覆层磨损量是磨损30 min时基体磨损量的43%,其磨损机制为磨粒磨损及摩擦磨损,750℃热震实验结果表明,熔覆层具有良好的耐磨抗力和热冲击抗力. 相似文献
11.
Steeliswidelyusedbecauseofitsgoodcompre hensive properties ,plentyofresourceandlowerprice .Thestrengthandtoughnessaretwoimpor tantpropertiesofsteels ,andpeoplemakeeffortstoincreasetheirvalues .Addingalloyingelementandcontrollingmicrostructurearetwobasicwaystoac complishtheaim .Therefinedmicrostructureob tainedbyprocessingtechniqueenablesthestrengthandtoughnessofsteeltobeincreasedwithoutaddingalloyingelementandtheratioofperformance costtobeincreased .Theultra finegrainedsteelshavefer ritegrains… 相似文献
12.
13.
FANG Chen-fu HE Bin ZHAO Zhong-chao HU Xiao-guang JIANG Jia-zhong SHI Zhen 《钢铁研究学报(英文版)》2013,20(4):81-86
Cable welding wire (CWW) CO2 gas shielded welding is an innovative process arc welding with high efficiency, high quality and low consumption, in which cable wire is used as consumable electrode. CWW CO2 gas shielded welding and submerged arc welding (SAW) are used for contrast studies on processing property of high strength steel A36 used in ship structure. The results show that the shapes of weld seam, using CWW CO2 gas shielded welding and SAW, are good and no weld defect such as air hole, flaw, slag inclusion, incomplete fusion, lack of penetration and so on are found in the weld seam. Because the rotating of arc during CWW CO2 gas shielded welding process has a strong stirring effect on molten pool, the grain in the heat affected zone (HAZ) of the joints, using CWW CO2 gas shielded welding, is small. Tensile failure positions of joints by CWW CO2 gas shielded welding and SAW are all in the base metal, but tensile strength of CWW CO2 gas shielded welding joint is higher than that of SAW joint by an average of 2. 3%. The average impact energy of HAZ, using CWW CO2 gas shielded welding and SAW, is almost equal, but the average impact energy of the weld seam using CWW CO2 gas shielded welding is increased by 6%, and the average impact energy of the fusion line is increased by 7%. The 180° bending tests for the joints of CWW CO2 gas shielded welding and SAW are all qualified, and the joints hardness is all less than HV 355, but hardness of CWW CO2 gas shielded welding wire welding joint near the fusion line is obviously lower. It can be concluded that the properties of CWW CO2 gas shielded welding are better than those of the SAW joint, and CWW CO2 gas shielded welding is suitable for welding high strength steel A36 used in ship structure. 相似文献
14.
按照EN 10225-2009附录E标准要求,采用50 kJ/cm大热输入埋弧焊工艺焊接厚为100 mm海洋平台用EH36钢板,测试分析了焊态及焊后热处理态焊接接头的组织与性能。结果表明,无论焊态还是焊后热处理态,EH36厚钢板焊接接头的硬度HV10≤280,抗拉强度≥510 MPa,-40℃冲击功均值≥50 J,表面组织以粗大的板条状贝氏体+少量粒状贝氏体为主,心部组织以细小的铁素体+珠光体为主,表明济钢开发的EH36厚钢板满足海洋平台的焊接生产要求。焊接接头表面与心部熔合线形状及传热状态的差异,是导致表面HAZ晶粒比心部粗大、因而表面韧性低于心部的主要原因。 相似文献
15.
FANG Chen-fu MENG Xiao-hui HU Qing-xian WANG Feng-jiang REN He WANG Hai-song GUO Yu MAO Ming 《钢铁研究学报(英文版)》2012,19(5):79-85
Compared with using semi-automatic gas shielded arc welding, using automatic TANDEM twin wire welding and twin wire gas metal arc welding (GMAW) to weld Q690 steel, a low-alloy high-strength structural steel used in the hydraulic support in the fully-mechanized mining face, the welding speed, deposition rate, production environment and welding quality can be obviously improved. Compared with GMAW twin wire welding, a refined microstructure in the weld and heat-affected zone (HAZ), narrow HAZ and improved joint strength were achieved with TANDEM on Q690. Also, due to the push-pull pulsed way in TANDEM welding, the droplet transfer, distribution on heat flow and interaction between two arcs were completely different from those in GMAW twin wire system. The heat input of TANDEM is only about 766% of GMAW, and correspondingly, the welding speed and welding seam can be obviously improved. The complete oscillation caused by TANDEM pulsed current occurred in the welding pool, which refined the grains in the microstructure. The results show that TANDEM twin wire welding is very suitable in the welding of Q690 used in the hydraulic support. 相似文献
16.
采用实物焊接和热模拟的方法研究了大型原油储罐用610MPa级高强度钢板大热输入焊接性能。结果表明,试验钢具有良好的抗大热输入量焊接的能力,原因是钢板中存在大量细小、弥散分布的TiN复合粒子,在焊接热循环的高温阶段,TiN粒子通过有效钉轧奥氏体晶界和促进铁素体晶内形核,抑制了焊接热影响区组织粗化;采用气电立焊和埋弧横焊焊接后,焊接对接接头的拉伸强度、低温冲击和冷弯性能优良,性能指标富余量大,试验钢板完全可以应用于10万m3及以上大型石油储罐的建造。 相似文献
17.
通过不同的手工电弧焊焊接工艺修补不锈钢复合板复层缺陷,并对修复的复合板进行化学成分、力学性能、显微硬度、金相组织、能谱等检测分析,结果表明,过渡层用309焊条、复层用308焊条、分两层修补的焊接工艺二修复的缺陷区,其力学性能及耐腐蚀性能满足复合板母材性能要求。 相似文献
18.
《钢铁研究学报(英文版)》2011,(Z1):983-986
590 MPa automobile beam steel strips are used mainly to manufacture the longitudinal beam of trucks.It’s welding properties are critical to the safety of truck.The microstructure and mechanical properties of welding joints processed by CO 2 arc welding with different welding parameters were studied.The results showed that the welding joints were weak when welding heat input were small and the non metal inclusions were found in the weld joints when welding heat input are big.The quality of the welding joints is good enough at 170A of the arc current and 24V of the arc voltage.Keeping the other welding parameters fixed,the incomplete fusion defect occurred in the welding joint with backward welding,but the quality of the welding joint is good with forward welding. 相似文献
19.
K. N. Gowtham M. Vasudevan V. Maduraimuthu T. Jayakumar 《Metallurgical and Materials Transactions B》2011,42(2):385-392
Modified 9Cr-1Mo ferritic steel is used as a structural material for steam generator components of power plants. Generally,
tungsten inert gas (TIG) welding is preferred for welding of these steels in which the depth of penetration achievable during
autogenous welding is limited. Therefore, activated flux TIG (A-TIG) welding, a novel welding technique, has been developed
in-house to increase the depth of penetration. In modified 9Cr-1Mo steel joints produced by the A-TIG welding process, weld
bead width, depth of penetration, and heat-affected zone (HAZ) width play an important role in determining the mechanical
properties as well as the performance of the weld joints during service. To obtain the desired weld bead geometry and HAZ
width, it becomes important to set the welding process parameters. In this work, adaptative neuro fuzzy inference system is
used to develop independent models correlating the welding process parameters like current, voltage, and torch speed with
weld bead shape parameters like depth of penetration, bead width, and HAZ width. Then a genetic algorithm is employed to determine
the optimum A-TIG welding process parameters to obtain the desired weld bead shape parameters and HAZ width. 相似文献
20.