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气流冲击造型主要参数的试验研究 总被引:1,自引:0,他引:1
引言气流突击造型是近几年发展起来的新的湿砂造型工艺。本文介绍了气流冲击造型主要参数的试验结果,有关数据可供设计时参考。本文还就气流冲击造型湿砂过程和有关重要参数进行了初步讨论。 相似文献
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对几种软隔膜覆盖砂型气流紧实进行了试验,结果说明以覆盖塑料薄膜的效果为好。但塑料薄膜覆盖对于模样顶面宽大,且深凹部的深凹比大的砂型的气流紧实的匀实性不利。 相似文献
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对8 mm厚SUS301L-MT不锈钢进行激光-MAG复合焊接,研究不同保护气流量对焊缝成形、显微组织和力学性能的影响。试验结果表明:当其他焊接参数一定时,在该试验条件下保护气流量对焊缝成形影响较小,焊缝区域组织相似,主要为柱状奥氏体树枝晶+少量的δ铁素体。接头显微硬度和冲击韧性随保护气流量的变化不明显。接头的抗拉强度随保护气流量的增加而提高,当保护气流量为40 L/min时,接头抗拉强度最高为765 MPa,达到母材抗拉强度的86.5%。分析拉伸断口发现,不同保护气流量断口微观形貌相似,断口中分布着大量韧窝,表现为韧性断裂。 相似文献
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高压气淬具有纯对流传热、易于控制、工件淬火后无需清洗和对环境影响小等优点。然而,典型的气淬设备显示出淬火料盘与工件之间的气流不均匀,导致工件的最终性能产生差异。业已发现,料盘的逆向气流布置是决定局部气流状态和热量传递的关键因素。尽管气流的主要部分在料盘与炉壁之间流动,对淬火过程不起作用,但是由料盘引起的流动阻力所产生的压降决定了淬火冷却强度。采用一种能较快收敛的多尺度模型对工业用高压气淬炉的内部流场进行了模拟,并通过速度测量和气流可视化技术对试验用淬火炉的内部气流进行了试验研究。最后,对圆柱体工件的双室真空炉淬火进行了模拟结果的验证,揭示了不同的逆向流速分布对淬火结果的影响。报道了多尺度模拟方法和流动过程的研究结果,并概述了对气淬工艺优化的指导性建议。 相似文献
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本文系统地总结了垂直底射和水平底射的试验;根据试验结果从理论上对实现底射的条件进行了分析;提出了经验数据、计算公式和确定底射工艺参数的方法。文章指出,防止砂层被气流击穿是实现底射的前提;在此前提下,通过砂层的气流速度和进气量大于某一定数值时,便可实现底射。控制射砂压力和送气时间可控气流速度和进气量的大小。本试验条件下,要实现底射要求射砂压力大于1.8k9/cm。,送气时间要控制在0.4~0.6抄之内。 相似文献
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Development, standardization and correlation of measurement methods to determine the effectiveness of corrosion inhibitors used in H2S/CO2 containing crude oil and natural gas The object of the research project was to simulate as closely as possible actual production conditions for crude oil and natural gas and in this manner 1. to test the meaningfulness of various test methods (stirred autoclave tests with rotating specimens, high pressure flow loop), 2. to develop a test method which allows a precise selection of inhibitors for corrosion protection, 3. to examine the usefulness of simple test methods as screening tests. By this means a more economic selection of inhibitors and materials for use in the field should be made possible. The results of the research program show that the proposed equipment options allow testing which correlates with actual practice. The autoclave method with rotating specimens allow parameter studies, i.e. the effects of the test parameters (temperature, H2S/CO2 ratio, flow) were correctly reproduced. The advantage of the flow loop is the better simulation of the flow conditions. The sequence of the inhibitor tests could be chosen such that a parameter study is first carried out at relatively low cost using the stirred autoclaves and the corrosion rates of the tubings and pipelines are then determined by targeted tests in the high pressure flow loop. 相似文献
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为使PIV(Particle Image Velocimetry)系统在流场测试中具有更高的可靠性、准确性和稳定性,根据PIV流场试验对CCD相机安装要求和工作环境的需求,设计了CCD相机位移调整机构,并阐述了该机构的设计思路、组成、能实现的功能及其特点。通过使用该机构进行流场试验,结果表明:采用该CCD相机位移调整机构,能很好地满足PIV系统在流场测试试验中的工作需要,使整个系统更加简单、稳定、高效,进而使流场测试结果更加可靠、准确。 相似文献
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This study aims to determine the plastic deformation characteristics of aluminum 5052-O based on non-associated flow rule. To achieve this goal, a new strain hardening model named as Kim-Tuan hardening model is proposed to perfectly describe the stress-strain relation of the studied material in terms of the uniaxial tensile test and to predict the material’s post-necking behavior. Additionally, the plastic behaviors of AL5052-O sheet are described by two approaches: the associated flow rule with YLD2000-2d yield function and the non-associated flow rule with Hill's quadratic function (NAFR-Hill48). The parameters of these functions were derived from the material properties that were obtained from uniaxial tensile tests and bulge test. The flow curve based on Kim-Tuan model and plastic behaviors obtained from two above-mentioned approaches were imported into a finite element analysis code to simulate the hydraulic bulge test for this material to confirm the precision of material characteristics achieved before. The simulation results based on the NAFR-Hill48 match well with the experiment results of bulge test while the YLD2000-2d provides highly accurate predictions for anisotropy of this material. 相似文献
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Contribution to corrosion behaviour of Alloy 33 in high concentrated sulfuric acid Investigations on the corrosive behaviour of Alloy 33 were conducted in 93% and 95–99% technical sulfuric acid at temperatures of 70–200°C. 6‐h‐tests with gravimetric evaluation and measurement of the free corrosion potential and 48‐h‐tests with gravimetric evaluation served to determine the influence of the sulfuric acid concentration and the temperature on the resistance of sheet samples at presence and absence of SO2. The influence of the flow rate was examined in 6‐h‐tests via rotation of pipe samples at circumferential speeds up to 2 m/s. The potential and gravimetric measurements showed that there is a resistance with ≤ 0.1 mm/a for Alloy 33 as from about 98.5% at temperatures from 100°C. However, about 125°C there seems to be a zone at which the resistance down to about 97.5% is kept at least for a long test duration. Examinations on the flow influence indicate that there is a reactivation in the said zone with increasing flow speed. However, the flow influence is low at the other temperatures. This extension of the resistance zone about 125°C proves that the temperature sensitivity of Alloy 33 is not monotonous in highly concentrated sulfuric acid. There are corrosion maxima and minima as a function of the sulfuric acid concentration at different temperatures. If SO2 is present, there is only a limitation of the resistance zone at low test temperatures, 80°C, 100°C in the 6‐h‐test and 70°C, 80°C in the 48‐h‐test. 相似文献
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针对目前常规管道检测机器人在大流速天然气管道内由于运行速度过快而导致无法应用的问题,提出利用速度控制装置对管道机器人进行主动调速。设计 610管道机器人速度控制装置,并对其开展了静态试验、动态试验和工业试验研究。静态试验压力可到10 MPa,有效检验了速度控制装置泄流阀在高压运转情况下的密封性及动作准确性。动态试验结果表明: 610速度控制装置泄流阀开启量在1/2区间对速度控制装置产生的压差影响最为明显,当泄流阀开启量超过 2/3 区间对速度控制装置产生的压差影响很小。工业试验针对带固定泄流孔的管道机器人启动力问题,测试了泄流阀开启固定泄流面积时的启动力,建立了泄流状态下机器人启动压差方程,并测试了速度控制装置的实际降速能力,为大口径、大流速工况下管道检测机器人的调速技术提供了理论和试验基础。 相似文献
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通过热压缩试验研究9Cr-2W耐热合金在1000~1300 ℃和应变速率0.005~0.5 s-1范围内的流变行为和热变形组织演变,并对热镦粗试样做了织构测定。分析该合金在实验参数范围内热变形的应力-应变特征,动力学方程,获得应力指数和变形激活能等表征其变形能力的重要特征参数。组织观察和织构测试结果表明,9Cr-2W耐热合金热变形过程中组织演变机制以动态回复和几何动态再结晶方式进行。在实际生产中,可以选择较高的变形温度来降低流变应力和改善各向异性。 相似文献
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吉林油田矿场条件下 CO2 腐蚀模拟装置的建立及实验研究 总被引:4,自引:4,他引:0
目的建立一种全尺寸腐蚀模拟放大试验装置。方法针对CO2驱油现场的实际情况,综合考虑影响CO2驱油腐蚀的各个因素,设计并研制更有效的高温高压CO2腐蚀模拟试验装置。对该装置开展模拟CO2腐蚀环境下,多种材料腐蚀特征及缓蚀剂防腐性能的实验研究,并将评价数据与室内高压釜实验、现场腐蚀监测的数据进行对比分析。结果该装置可实现液态CO2流量0~0.9 m3/h、温度-25~120℃、最高压力32 MPa下各种矿场腐蚀环境的模拟,能够模拟常规室内研究设备无法模拟的低温-高温高压条件下的多相流动状态,与现场流态更为接近,模拟结果可有效指导CO2驱油与埋存工程防腐工艺的制定。结论表面矿场条件下的CO2腐蚀模拟数据接近矿场实际腐蚀监测数据,实现了井筒、地面设备管道材料和防腐工艺技术的矿场模拟评价。 相似文献