螺旋半圆管夹套的制造工艺

螺旋半圆管夹套的制造工艺东北制药总厂建安公司陈辉螺旋半圆管夹套（以下简称半管）设备在欧美国家已较普遍使用，且德国于１９ｗ年已形成规范化．半管设备与普通夹套容器相比，具有简体受力好、传热效率高、节能及节约钢材用量等优点，是目前较为合理、先进的夹套结构．...     

浅谈半圆管夹套的优越性

浅谈半圆管夹套的优越性哈尔滨制药厂谢振清哈尔滨建成机械厂赫荣焱哈尔滨制药厂孙振龙目前，在我国医药、化工等行业，半圆管夹套正以其独特的优越性，被越来越多地采用。在我们的设计中，也多次采用了这种结构，并在实际生产中收到良好效果，现将其特点介绍如下。首先是...     

螺旋半圆管夹套式反应器的结构特点和开发应用

该文从容器结构的经济性和提高传热效率两个主要方面,着重论述了螺旋半圆夹套式反应器开发与应用的实际意义。     

半圆管夹套规范设计方法与有限元分析的比较

半圆管夹套广泛应用在化工、制药、食品等工业装备上。以食品设备上的半圆管夹套为例，按三种不同的设计规范（原苏联ΓOCT25867－83、美国ASME Ⅷ－1 1992及原德国DIN28128）来计算其夹套许用压力，然后利用有限元方法对半圆管夹套进行应力分析，结果表明，按AD规范设计的半圆管夹套，材料的利用更合理。     

304不锈钢半管夹套焊接部位残余应力有限元模拟

半圆管夹套设备最常见的问题是夹套焊接部位开裂引起泄漏。焊接残余应力是重要的影响因素之一。本文利用有限元软件ABAQUS，开发了一个顺次耦合的焊接热应力计算程序，讨论坡口形式、线能量、半管间距等参数的变化对焊接残余应力的影响，得到了半管结构残余应力分布特征，找到了最大焊接残余应力的位置及大小，为半管夹套的安全评定提供参考。     

蜂窝夹套容器的焊接制造

蜂窝夹套容器是由杜邦公司从工艺角度提出的一种新型容器,其制造难点和关键技术是蜂窝孔的焊接。本文讨论了蜂窝孔的焊接结构设计和工艺选择,介绍了焊接质量控制措施和防焊接变形技术。该设备的制造成功对我国此类压力容器的设计制造提供了成熟的经验。     

冷冻机水夹套裂缝焊接修复

针对冷冻机铸铁水夹套的裂缝及其特点与形式,制定了简便实用的冷焊修复工艺,为了控制和减小铸件的焊接应力,采取了有效的焊接工艺方法,使焊接修复工作取得了满意的结果。     

奥氏体不锈钢的焊接工艺

本文以焦罐底门为例,针对18-8型奥氏体不锈钢的焊接特点,深入研究分析各种问题,逐步形成了有效的焊接工艺路线,对生产实际中此种类型的不锈钢件焊接具有很好的指导意义。     

加强夹套封口焊缝的质量检验

在夹套设备的破坏事故中,绝大多数的问题发生在夹套封口环与内筒焊接的焊缝处。该条焊缝在GB150—89《钢制压力容器》(以下简称“国标)和《压力容器安全技术监察规程》(以下简称“容规”)中均未提出设计、制造及检验的细节和有关要求。在国标中该条焊缝一般归属于D类焊缝,在夹套设备施工图纸的技术条件中,也未对该焊缝提出任何要求。因此,制造单位在检验中也未引起足够的重视,仅用     

大直径夹套翻边段的成形工艺

带夹套压力容器夹套上口端的封闭结构一般均参照GB150—89《钢制压力容器》附录K的规定设计,常用的结构形式见图1。在夹套直径较小和壁厚较薄时,可以采取以下成形工艺: 1.将夹套翻边段先卷制成直筒、加热、用胎具整体冲压成形,夹套筒体较短时.也可直接在     

Study on mechanical properties of austenitic stainless steel depending on heat input at laser welding

The austenitic stainless steels used in various industrial fields require low heat input for welding. Laser welding is an excellent welding method in this respect. This study investigates the effect of laser welding speed on the mechanical properties at welding speed of 1.0, 1.5 and 2.0 m/min, using STS304L of austenitic stainless steel. The microstructures of fusion zone (FZ) show a two phase structure consisted of austenite and δ-ferrite, and δ-ferrite in the fusion zone tend to decrease with increase of welding speed. Meanwhile, the mechanical properties were excellent at the welding speed of 1.5 m/min for tensile, bending and impact tests.

     

Numerical study of welding simulation and residual stress on butt welding of dissimilar thickness of austenitic stainless steel

It has been well documented in the literature the importance of strict surface integrity checks upon performance and quality of machined components, especially for the safety critical components (e.g., aerospace) that work at cyclic high mechanical loads and elevated temperatures. In this field, Waspaloy, within the commercially available nickel-based superalloys, is extensively applied in different industries such as aircraft, chemical plant equipment, and petrochemical equipment. The main objective of this paper is to implement a reliable FE model, for dry orthogonal machining of Waspaloy, capable to predict microstructural changes and dynamic recrystallization during the cutting process. A user subroutine was implemented in FE code to simulate the dynamic recrystallization and consequently grain refinement and hardness variation on the machined surface and below it. Zener–Hollomon (Z-H) and Hall–Petch (H-P) equations were employed to, respectively, predict grain size and microhardness. In addition, depth of the affected layer was controlled using the critical strain equation. FE numerical model was properly calibrated using an iterative procedure based on the comparison between simulated and experimental results. Finally, very good agreement was found between experimental and simulated results of grain size, microhardness, depth of the affected layer, and other fundamental variables such as cutting forces, temperature, and chip morphology.     

陶瓷刀具切削奥氏体不锈钢的切削力试验研究

对3种复合陶瓷材料刀具切削奥氏体不锈钢(1Cr17Ni7)进行研究,建立了正交切削试验方案.通过试验研究了切削用量对三向切削力的影响,利用指数回归分析建立了3种刀具的主切削力经验公式,并结合切削用量显著性分析对主切削力进行了对比分析.试验结果表明在采用较小进给量和较小切削深度进行切削时,会出现了背吃刀力大于主切削力的现象；切削速度及进给量对主切削力的影响最大；3种刀具中CT2刀具的主切削力最大.     

Investigation on the resistance spot-welded austenitic/ferritic stainless steel

In this work, the effect of weld current on joining capability of austenitic stainless steel (AISI 304) and ferritic stainless steel (AISI 430) sheets with application of resistance spot welding process was investigated. Macrostructure, microstructure, microhardness, tensile shear strength, and failure mode of welded materials were evaluated for different weld currents. The values of weld current were 2.5, 3.75, and 5 kA. It was found that when the weld current increased, the nugget size and the weld strength were increased. Two distinct failure modes including interfacial and pullout were observed during tensile shear test. Finally, an adequate weld current was obtained.     

Effect of contact pressure on fretting fatigue of austenitic stainless steel

The effect of contact pressure on fretting fatigue in solution-treated austenitic stainless steel was studied. With an increase in contact pressure, fretting fatigue life was almost unchanged at low contact pressures, however it decreased drastically at high contact pressures. At low contact pressures, stress concentration due to fretting damage occurred at the middle portion of the fretted area and the main crack responsible for failure was initiated there. At high contact pressures, concavity was formed at the fretted area without accompanying heavy wear. The main crack was initiated at the outer edge corner of the concavity which probably acted as a notch. Plain fatigue prior to the fretting fatigue test increased the fretting fatigue life at high contact pressures since the concavity formation was suppressed by the cyclic strain hardening.     

304不锈钢A-TIG焊的试验研究

主要研究在304不锈钢焊接时涂敷活性焊剂和未涂敷活性焊剂对焊缝成形的影响。试验结果表明304不锈钢采用A-TIG焊时,涂敷活性焊剂的焊缝熔深显著增加,熔宽有所减小;活性剂使熔池横截面形状发生明显变化,即焊缝上部比较宽、中下部变得很窄,这主要是由表面张力梯度的变化引起的。     

Tribological properties of nickel-base nanocrystalline coatings sputter-deposited on austenitic stainless steel

500 nm-thick films are deposited on austenitic stainless steel by neutral (Ar⁺) or reactive (N⁺) ion beam sputtering of Ni or NiTi targets, with (or without) high energy 160 keV-Ar⁺ ion beam assistance. Most of the time the coatings are nanocrystalline and induce a large (excellent in some conditions) increase of the wear resistance. Only Ar⁺ ion beam sputtering of a NiTi target gives an amorphous deposit which does not improve the substrate tribological properties. The hardness and wear resistance of ion beam assisted films are larger than those obtained with non-ion beam assisted coatings. The presence of a hard TiN phase inside a ductile Ni phase, of grains with preferential orientation beneficial to slip, as well as film densification are the main factors which increase the wear resistance. The best results are obtained when the structure is composed of two phases, Ni and TiN. The TiN phase strengthens the already good tribological Ni properties and the Ni ductility induces mechanical accommodation during the friction process.     

Influence of shielding gas mixtures on bead profile and microstructural characteristics of super austenitic stainless steel weldments by laser welding

A planned and orderly analysis of the microstructures and bead profiles of AISI 904 L super austenitic stainless steel bead-on-plate welds was accomplished by coupling up diffusion cooled slab 3.5?kW CO₂ laser with two dissimilar shielding gaseous mixture namely 100% nitrogen (N) and 50% argon?+?50% nitrogen (A?+?N). AISI 904 L Super Austenitic Stainless Steel (SASS) incorporates higher levels of Mo, Cr, Ni, N, and Mn under normal conditions. In heating applications, it offers a superior corrosion resistance at moderate and higher temperatures. The microstructure of SASS is exhaustively austenitic in nature, when subjected to a solution-quenched state. The objective of this study is to determine the phenomenon that follows the action of two shielding gas mixtures on microstructural and bead profiles of laser-welded 904 L SASS. The weld bead profile of laser welding depends on various parameters such as beam power; travel speed, and focal position of the laser spot, and these factors have to be chosen in an appropriate manner to obtain the desired output. The cross-sectioned area of the bead profiles like bead width and depth of penetration is measured using an optical microscope. Two different shielding gas mixtures were used to examine the microstructural changes in the weld region. Besides, the variation in the hardness of the weld region was analyzed through the Vickers hardness tester.     

Study of laser butt welding of SUS301L stainless steel and welding joint analysis

This paper describes a study on laser butt welding of 4 and 2 mm SUS301L stainless steel and a detailed analysis of welding joints. The gap tolerance of butt joint was also studied with optimized process parameters. The electrolytic etching in 10 % oxalate solution was used to test the intergranular corrosion of the 4 mm SUS301L welded joint. Fatigue property of the 2 mm SUS301L welded joint was tested under the conditional cycle times of 1?×?10⁷. Using optical microscopy, the changes of metallurgical microstructure in the weld zone of 4 mm SUS301L were also studied. It has been found that laser butt welding of 4 mm SUS301L is able to achieve sound metallurgical morphology and high strength weld joint when the butt gap is within certain tolerance. The weld joint also has good resistance to intergranular corrosion and has a fatigue limit of 310 MPa.