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1.
采用熔化极气体保护焊,在5 000kW铰刀功率自航式绞吸挖泥船耳轴端外衬套内壁进行镍基合金堆焊,并对堆焊接头进行焊接工艺性能试验。结果显示:采用CHM-NiCrMo-3焊丝并选取适当试验参数焊接的堆焊接头其焊缝成形、硬度、宏观腐蚀形貌、探伤等均满足客户及相关技术规范的要求。此镍基焊材及堆焊工艺已应用于自航式绞吸挖泥船的生产制造中,效果良好。  相似文献   

2.
日本《溶接学会志》1986年№1一则报道指出,近几年来管状焊丝在结构焊接中得到了广泛的采用,其需量还在迅速增加。为使管状焊丝的焊接高效率化,需要从焊丝的特性方面来提高熔化速度和熔敷效率,设想从增加电流密度和利用焊丝预热效果等方面提高焊丝的熔化速度和减少飞溅量等提高熔敷效率。在这些重要因素中,需调查焊丝直径和焊接电流值对电流密度的影响和焊丝的外伸长度(焊嘴与母材之间的距离)对预热效果的影  相似文献   

3.
针对400ft钻井平台桩腿齿条板与半圆板焊接全熔透的新要求,笔者通过试验和不同施焊方法相结合的方式分析了组对间隙和清根与否等因素对Q690E试板接头根部熔深的影响。结果表明,无论采用何种焊接方法,反面清根后施焊,接头熔合状况均良好,且采用实芯焊丝比药芯焊丝接头熔深大。正面气保焊打底,反面不清根采用气保焊施焊,接头熔合不良;而反面采用埋弧焊施焊,接头可实现熔透,但工艺还有待优化,以避免结晶裂纹的产生。  相似文献   

4.
根据疏浚船舶性能要求,首先对DH36钢的力学性能进行试验研究,结果证明其具有良好的焊接性能及抗冷裂纹性。然后根据项目情况采用手工电弧焊、药芯焊丝气体保护焊、埋弧自动焊三种焊接方法。对所选焊条CHE50、药芯焊丝SQJ501L、埋弧焊丝CHW-S3/焊剂CHF102进行性能试验,结果证明其力学性能与DH36相匹配。然后进行三种焊接方法的工艺评定试验,结果证明手工电弧焊,焊接线能量控制在1.4~1.7kJ/mm;CO2药芯焊丝气体保护焊,焊接线能量控制在1.3~1.8kJ/mm;埋弧自动焊,焊接线能量控制在1.6~2.0kJ/mm,均可获得良好的焊接接头性能。  相似文献   

5.
通过实验,得出了MAG焊气体混合比对熔敷效率、飞溅率、熔敷速度和焊丝熔化速度等熔敷特性的影响规律,分析讨论了保护气体性质对MAG焊熔敷特性影响的原因。  相似文献   

6.
依据英国BS7448断裂韧性试验标准,对番禺30-1深海导管架项目广泛应用的超大尺寸焊接接头的低温CTOD断裂韧度进行了探讨.对采用手工电弧焊(SMAW)和药芯焊丝气体保护焊(FCAW)工艺施焊的大尺寸板厚的海洋石油平台焊接接头试样进行了CTOD试验.分别测试了0℃两种工艺下焊缝金属和热影响区的CTOD断裂韧性,对试验结果进行了分析讨论.试验表明,除药芯焊丝气体保护焊热影响区接头两个试样数据无效外,其余试件均满足挪威船级社DNV规定的最小特征CTOD为0.15mm的要求.这说明95mm的D36-Z35钢板手工电弧焊和药芯焊丝气体保护焊焊接接头可以在不进行焊后热处理的情况下使用.试验结果为免除这种板厚焊接接头的焊后热处理提供了依据,这对于海洋平台大型焊接结构来说,可以大大降低制造成本,缩短生产周期,具有巨大的经济意义.  相似文献   

7.
集装箱生产中焊接缺陷的形成原因分析及预防   总被引:1,自引:0,他引:1  
1 焊接 焊接是将两种或两种以上材质(同种或异种),通过加热或加压或两者并用来达到原子之间的结合而形成永久性连接的工艺过程。在集装箱生产中广泛采用的是熔化极混合气体保护焊(MAG焊)这种焊接属于焊接方法分类中的熔化焊范畴。即利用电弧局部加热连接处的金属,使之熔化,再以熔化的CO2气保焊丝作为填充金属;依靠熔化金属的冷却凝固而将集装箱各部件连接起来的焊接方法。  相似文献   

8.
采用不同焊接工艺对2205双相不锈钢进行焊接,分析不同焊接工艺对焊接接头力学性能、微观组织及耐腐蚀性能的影响。结果显示:在晶粒无明显长大时,焊缝及热影响区冲击韧性随奥氏体质量分数的增加而升高;采用熔化极气体保护焊(Gas Metal Arc Welding,GMAW)时,保护气体中加入N2可有效提高焊接接头各区域奥氏体质量分数,从而提高焊接接头力学性能及耐腐蚀性能;2205双相不锈钢母材及焊缝腐蚀速率均明显随腐蚀液质量分数的升高而增加。优化双相不锈钢焊接工艺参数,保证其焊接接头具有良好的综合性能,对于该类材料构件及产品的制造、推广及使用意义重大。  相似文献   

9.
本文介绍了日本造船焊接工艺的发展:1965年开始单面埋弧自动焊和大合拢分段立向对接接头的气电垂直自动焊;1975年前后大力推广重力焊;1980年起采用熔渣型药芯焊丝的CO2气体保护焊;1983年以后,开发了各种简单自动焊CO2气体保护焊机和多丝自动焊专用装置,实现1人多焊机的设想,推动了焊接机械化的进展。进入九十年代以后,  相似文献   

10.
以Ar CO2作为保护气体,研究了实芯焊丝MAG焊的混合气体配比、焊接电流、电弧电压和气体流量对熔敷速度、熔敷系数和熔敷效率的影响。结果表明,Ar气比例越大,熔敷效率越高,Ar气比例达到80%以上,熔敷效率显著增加。适当的焊接工艺可获得较高的熔敷速度、熔敷系数和熔敷效率。  相似文献   

11.
Errata     
正In the paper"Influence of Fouling Assemblage on the Corrosion Behaviour of Mild Steel in the Coastal Waters of The Gulf of Mannar,India"in Vol.12,No.4,Page:509,References were lost,and the two authors’biographies were identical.The correct text is shown below.We apologize to the authors and our readers for any inconvenience caused by the errors.  相似文献   

12.
13.
正St.John's,Newfoundland,Canada,May 31-June 5,2015 OMAE2015 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to: meet and present advances in technology and its scientific support;  相似文献   

14.
正San Francisco,California,June 8-13,2014.OMAE 2014 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to:·meet and present advances in technology and its scientific support;·to exchange ideas and experiences whilst promoting technological progress and its application in industry·to promote international cooperation in ocean,offshore and arctic engineering.In line with the tradition of excellence of previous OMAE conferences,more than 900 technical papers are planned for presentation.Outreach for Engineers Specialty Forum This Specialty Forum is designed for students and professionals who may not be familiar with the Ocean and Offshore industry,as well as those who have just recently specialized in this field.  相似文献   

15.
联合作战计划和执行系统   总被引:2,自引:1,他引:1  
全球指挥控制系统(GCCS)实施当前美国海军网络中心战信息基础设施的联合计划网络。联合作战计划和执行系统(JOPES)支持GCCS实现联合计划。JOPES有两类计划:时间不限的精密预案计划生成作战计划、方案计划或职能计划;时间敏感的危机行动计划生成作战命令或战役方案。前者在和平时期创建的作战计划是后者的计划基础,加速应付危机的能力。  相似文献   

16.
Recent measurements of wave induced hull strain and flexure in RN warships are presented together with the derivation of the current design criteria for extreme hull girder bending loads. The history of the development of the shipboard instrumentation used is given and recent developments to improve the quality and ease of analysis of the data are described. An unexpectedly high transverse asymmetry in the longitudinal strains measured in destroyers is shown to be the result of a combination of vertical and lateral bending in oblique seas. Finally recent theoretical comparisons between the loading of Deep-Vee hulls and conventional UK rounded bilge hulls are presented which demonstrate the higher loading experienced by this type of hull form.  相似文献   

17.
正19–24 October 2014 SingaporeCONFERENCE THEMES The overall aim of the ICHD Conference is to provide a forum for participants from around the world to review,discuss and present the latest developments in the broad discipline of hydrodynamics and fluid mechanics.The first International Conference on Hydrodynamics(ICHD)was initiated in 1994 in Wuxi,China.Since then,9 more ICHD conferences were held subsequently in Hong Kong,Seoul,Yokohama,Tainan,Perth,Ischia,Nantes,Shanghai and St Petersburg.Evidently the ICHD conference has become an important event among academics,researchers,engineers and operators,working in the fields closely related to the science and technology of hydrodynamics.The 11th ICHD will be held in Singapore in 2014.  相似文献   

18.
正November 4-6,2014Moody Gardens HotelConvention Center/Galveston,TX The Deepwater Operations Conference and Exhibition is celebrating its 12th anniversary this year.This growing event will continue the tradition of excellence in addressing operational challenges involved in developing deepwater resources.We will return to the Moody Gardens Hotel and Convention Center on November 5-7,2014 in Galveston,Texas.  相似文献   

19.
In terms of equal sailing distances, where is the inflexion when ships depart from ports in the Asian Continent to New York via Suez and/or Panama?
The answer is China South Port Group (Hong Kong, Shenzhen and Guangzhou).  相似文献   

20.
Despite the many socio-economic similarities between Sweden and Norway, differences in jurisdiction, organisation, cooperation, and financing of long-distance passenger train and coach services have led to the development of four distinctively different ways of serving the markets. This paper describes how the train and coach markets have developed in the two countries, with emphasis on regulatory and industrial structure and a couple of performance variables.Looking at passenger rail, both countries separated infrastructure from operation over a decade ago. However, while Norwegian rail is characterised by an almost monopoly supplier, rail services in Sweden are partly decentralised to the responsibility of county authorities and are widely subjected to competitive tendering. The rest of the network is about to be opened up for on-the-track competition. Swedish Rail (SJ) has spent the last decades consolidating its core business (passenger rail) and sold out its other businesses. In contrast, the Norwegian state rail (NSB) has expanded its business to become a major bus operator and property owner, with extensions also into the Swedish market.The coach industry was more recently deregulated in both countries. The Swedish coach market is dominated by privately owned companies operating services to and from Stockholm. In Norway, state-owned NSB is a major coach operator on medium distance routes, and is also the largest partner of Nor-Way Bussekspress which totally dominates long-distance coach services. Further, the Norwegian coach market is characterised by cross-ownership and cooperation which has enabled an extensive route network which covers most of Norway.We find distinct differences in achievements in the two modes and in the two countries. Swedish rail services have succeeded in winning market shares and in renewing and developing both infrastructure and service levels to a greater extent than the Norwegian model. On the other hand, the Norwegian coach market seems to be more developed and efficient compared to its Swedish counterpart.The paper concludes with a discussion on the possible links between the different approaches and the performance observed, with the aim to stimulate further and more detailed research on some important issues.  相似文献   

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