燃?xì)馔钙绞綁嚎s機(jī)的結(jié)構(gòu)設(shè)計(jì)
燃?xì)馔钙绞綁嚎s機(jī)的結(jié)構(gòu)設(shè)計(jì),燃?xì)?透平,壓縮機(jī),結(jié)構(gòu)設(shè)計(jì)
畢業(yè)設(shè)計(jì)（論文）中期報(bào)告
題目：燃?xì)馔钙绞綁嚎s機(jī)的機(jī)構(gòu)設(shè)計(jì)
系 別
專 業(yè)
班 級(jí)
姓 名
學(xué) 號(hào)
導(dǎo) 師
（居中，四號(hào)，宋體，行距30磅）
年 月 日（居中，四號(hào)，宋體）
1.設(shè)計(jì)（論文）進(jìn)展?fàn)顩r
本設(shè)計(jì)已經(jīng)完成以下內(nèi)容：
（1）對(duì)于在開題答辯中，老師對(duì)我開題報(bào)告中提出的相關(guān)問題進(jìn)行了修改，并通過了指導(dǎo)老師的檢查。
（2）明確了透平式壓縮機(jī)具體設(shè)計(jì)思路、設(shè)計(jì)方案與框架，并完成了外文資料的翻譯。本設(shè)計(jì)設(shè)計(jì)的是透平式壓縮機(jī)中的離心式，離心式壓縮機(jī)的基本原理是通過原動(dòng)機(jī)帶動(dòng)轉(zhuǎn)子部分的旋轉(zhuǎn)，使進(jìn)入壓縮機(jī)的氣體通過葉輪、擴(kuò)圧器、彎道、回流器，反復(fù)地得到旋轉(zhuǎn)加速加壓的效果，并通過逐級(jí)的加速加壓，最后達(dá)到設(shè)計(jì)所需的氣體速度和壓力要求，如圖1.1所示。
圖1.1 壓縮機(jī)工作原理示意圖 圖1.2 壓縮機(jī)級(jí)內(nèi)截面劃分
（3）對(duì)燃?xì)馔钙绞綁嚎s機(jī)的主要結(jié)構(gòu)進(jìn)行了參數(shù)設(shè)計(jì)和計(jì)算，包括壓縮機(jī)缸體的氣動(dòng)計(jì)算，壓縮機(jī)強(qiáng)度軸向推力的設(shè)計(jì)計(jì)算與效驗(yàn)以及密封的設(shè)計(jì)。
為了計(jì)算氣體流過葉輪時(shí)，葉輪對(duì)氣體所作的功，需先分析氣體的運(yùn)動(dòng)情況。氣體在一級(jí)里所作的運(yùn)動(dòng)劃分如圖1.2所示：
考察常規(guī)葉輪的截面1－1及截面2－2（圖1.2），1－1截面是氣體剛進(jìn)入葉片的截面，2－2截面是氣體即將離開葉片的截面，設(shè)截面上氣流的絕對(duì)速度，牽連速度與相對(duì)速度分別以c、u及w表示,，則當(dāng)氣流以進(jìn)入1－1截面時(shí)，其相對(duì)速度：
1－1截面是氣體剛進(jìn)入葉片的截面，2－2截面是氣體即將離開葉片的截面，設(shè)截面上氣流的絕對(duì)速度，牽連速度與相對(duì)速度分別以c、u及w表示,，則當(dāng)氣流以進(jìn)入1－1截面時(shí)，其相對(duì)速度：
而當(dāng)氣流以離開2－2截面時(shí)，其絕對(duì)速度：
式中的指截面上的圓周速度，其大?。?
圖1.3表示出了c、w及u三個(gè)速度矢量的關(guān)系，它們組成的三角形表示出了三者之間的數(shù)量關(guān)系，稱為速度三角形。
圖1.3 葉輪進(jìn)出口截面氣流速度分析
a)進(jìn)口速度三角形 b)出口速度三角形
在圖1.3中，a）的正值指c與u之間的夾角，而β的正值指w與u的反向之間的夾角。今后常需把速度分解為圓周方向（即u方向）及垂直于u方向（在常規(guī)葉輪中即為半徑r方向）的分量，由圖1.3，對(duì)出口速度三角形作幾何分析可得：
而且從速度三角形可得下述關(guān)系：
對(duì)于進(jìn)口速度三角形，同樣有如下關(guān)系式：
及
cu有時(shí)被稱為旋繞，而cu1被稱為預(yù)旋，在大多數(shù)設(shè)計(jì)工況時(shí)，cu1＝0（或），此時(shí)稱為“無預(yù)旋”情況。
軸向推力計(jì)算示意圖，如圖（1.4）所示：
圖1.4 壓縮機(jī)軸向推力計(jì)算示意圖
（4）繪制總裝配圖，如圖1.5所示。離心式壓縮機(jī)的本體結(jié)構(gòu)分為兩大部分：轉(zhuǎn)子，定子。轉(zhuǎn)子由主軸、葉輪、平衡盤、定距套、推力盤、半聯(lián)軸節(jié)等部分組成。定子由氣缸、隔板、支撐軸承、推力軸承、軸端密封等零部件組成。
圖1.5 透平式壓縮機(jī)總裝配圖
2.存在問題及解決措施
存在的問題：本設(shè)計(jì)雖然已經(jīng)完成重要設(shè)計(jì)參數(shù)的計(jì)算，但燃?xì)鈮嚎s機(jī)對(duì)設(shè)備的密封性和防暴阻燃要求很高，在設(shè)備的密封和防暴阻燃性能存在很大的疑慮。此外本設(shè)計(jì)涉及到了許多非標(biāo)準(zhǔn)件的選用，綜合考慮結(jié)構(gòu)和經(jīng)濟(jì)性人不是很合理。
解決措施：認(rèn)真查閱參考資料，向老師請(qǐng)教，與同學(xué)交流，繼續(xù)完善設(shè)計(jì)，以設(shè)計(jì)圖紙為突破口優(yōu)化結(jié)構(gòu)，以求更加合理準(zhǔn)確。
3.后期工作安排
對(duì)壓縮機(jī)零件進(jìn)行優(yōu)化改進(jìn)，進(jìn)而促使壓縮機(jī)結(jié)構(gòu)更加優(yōu)化。改進(jìn)中期設(shè)計(jì)中存在的缺點(diǎn)，比如壓縮機(jī)裝配時(shí)可能出現(xiàn)的互相干涉無法組裝、設(shè)計(jì)時(shí)沒有考慮加工難度從而導(dǎo)致制造成本高等等缺陷。
第12周(2015年3月23日—2015年3月29日)：對(duì)中期答辯提出的問題進(jìn)行修改，完善中期報(bào)告的內(nèi)容和格式并提交；
第13-14周(2015年3月30日—2015年4月19日)：繪制零件圖，開始畢業(yè)論文撰寫；
第15-16周(2015年4月20日—2015年4月26日)：完善零件圖，完成畢業(yè)論文撰寫；
第17周(2015年4月27日—2015年5月3日)：修改論文格式并準(zhǔn)備畢業(yè)答辯。
指導(dǎo)教師簽字：
年 月 日
注：1）正文：宋體小四號(hào)字，行距20磅，單面打??；其他格式要求與畢業(yè)論文相同。
2）中期報(bào)告由各系集中歸檔保存，不裝訂入冊(cè)。
附錄A 英文原文
The entire machine bucket centrifugal compressor gas seal positioning the Boss Welding
Liu Dongju Hafu the Indian Ocean Tong Ming-chen / Shenyang Blower (Group) Co., Ltd.
Abstract: The cylinder-type centrifugal compressor gas seal Boss caused due to operational deficiencies, so as to the Welding Technology. Welding on the choice of methods were compared, specifying the use of hand-TIG welding method of Welding Technology Practice has proved that good results.
Key words: centrifugal compressor seal Boss Welding
CLC: TH452 code: B
Rep air Welding of Allocating Convex for Dry Ga sSeal in Barrel Typ e Centrifugal Compre ssorAbstract:Repair welding technology of allocatingconvex for dry gas seal in barrel type cent rif ugalCompressor caused by operation fault is int ro2duced.The selections of repair welding technolo2gy are compared,and t he repair welding technol2ogy using handwork gas t ungsten arc welding isdetailed.The result wit h good effect is got.Key words:Cent rif ugal Compressor Seal convexRepair welding
1.Introduction
Taiwan assembly in a tube-type gas compressor seal, found in the left and right end cancelled with the installation of dry gas seal, by drilling a vent drilling dry gas seal positioning Boss, Boss to seal damage, destruction of Up to 25 mm × 10mm × 7mm (see Figure 1 in the F), resulting in dry gas seal targeting local plastic ring seal bad.
Left and right to cover their own water pressure test, the pressure for the 30 M Pa, after passing the cover and chassis pressure test done at the same time, pressure to 20 MPa, medium for helium. The product of the media for circulating hydrogen gas, under pressure 16 MPa; if not sealed Boss Welding not only affects the appearance quality is more important to the functioning unit will be sealed leak caused a serious, but will also affect gas The use of sealed, leading to paralysis and crew shutdown process, the consequences would be unthinkable.
Left and right cover material for KMN materials, the special material, very difficult Welding, the left and right cover has been finished, if Welding improper measures will cause cracks, after welding deformation, the most serious is the result of the components scrapped.
Figure 1 Cover Welding regional plans
2 KMN briefing materials
KMN material is my company centrifugal compressor impeller welding, end caps, and other special materials. The material for chromium molybdenum alloy, solder needed before preheating, after welding need to heat treatment, in the use of state-quality, complex welding process, welding materials used KMN dedicated electrode.
3 Welding Methods Laser
3.1 cold welding
As left and right cover has been finished, dry gas seal targeting Taiwan has finished processing, welding heat input will lead solder after deformation. To prevent deformation after welding, welding is the preferred method of cold welding. In order to ensure the quality of Welding, the author and the Chinese Academy of Sciences Institute of metal surface laser fusion of professional and technical personnel, the quality of the scene, can be used to confirm whether the cold welding method Welding. Laser fusion welding surface of the technical staff to cover KMN of performance, welding, etc., are familiar, Welding position in the middle of the cover, to confirm the repair welding electrodes when contact is very difficult, even if exposure to welding electrodes Efficiency is very low, quality is difficult to ensure that, in the face of this situation, it is not appropriate to confirm the laser cold welding.
3.2 manual arc welding
Using manual arc welding to repair welding, flexible. As KMN material is material for the company, has dedicated KMN electrode, welding materials and welding no problems after the performance. Welding is to be the key to the left and right end caps are in place after finishing the dry gas seal region, Welding before preheating required welding, heat treatment after welding, manual arc welding of the great heat input will increase Welding The regional heat input, heat input of the constantly increasing, and will lead solder after deformation. If a deformation, which means that the left and right cover will be scrapped, we should not use this method.
3.3 manual TIG welding
Welding is the use of argon gas for the protection of a welding method. Welding, argon arc in the formation of the protection of the surrounding gas, molten metal, tungsten wire and extremism is not the first contact with air. Argon is an inert gas, it does not react chemically with the metal, very stable. Therefore, in the process of being welded metal and welding wire in the alloying elements not burning. In addition, Argon do not dissolve in metal, it can not be formed in the metal in the stomata. With these characteristics, can be used welding quality of the weld.
The use of welding parts to repair welding, more fully the reasons are:
(1) As the argon arc by the compression and cooling, allowing more concentrated arc energy, small heat-affected zone, the deformation is small;
(2) Weld Central slag, welder in operation can clearly see the pool and the formation of the weld, easy to operate;
(3) operation from space location restrictions, suitable for all-position welding;
(4) suitable for welding and non-ferrous metal alloy steel, stainless steel, high-temperature alloy steel, special steel and refractory metals such as the activity.
Based on the characteristics of welding, using welding on the left and right cover to seal the Welding most appropriate.
4 .manual TIG welding Welding Technology
4.1 welding technical parameters
Equipment Model: Osaka, Japan OTC company's AC2CU TI G 300 P pulse welding machine;
Power Polarity: DC is received;
Tungsten: Ce tungsten; diameter: Φ3.2 mm; Extended Length: 7 mm;
Argon purity: 99.99%; argon gas flow rate: 8 L / min;
Nozzle diameter: 10 mm; tungsten extreme workpiece distance: 4 mm;
Arc: by high frequency arc-arc;
Welding current: 110 ~ 120 A;
Welding voltage: 20 ~ 22 V.
4.2 welding pre
(1) Welding with the oil-alcohol, acetone thoroughly cleaned.
(2) check the power, water, gas, such as whether or not the normal way.
(3) KMN Φ3.2 mm electrode-skin cleared, sandpaper after finishing with acetone clean, do Welding filled with wire.
4.3 points
(1) arc advance of 5 ~ 10 s transmission argon, in order to rule out the possibility of Welding and welding pieces by the air-conditioning argon gas flow.
(2) Welding the first layer using the left-welding method, the second layer by the right-welding, and from then to Welding. After a weld seam equivalent to a pre-tempered, eliminate stress the role played by the left-welding, the right-welding, turn to each other Welding of meat, until the end of the welding.
(3) Welding short arc welding used to enhance the protection, but will reduce the width of the heat-affected areas and to prevent deformation of Welding.
(4) filled wire to uniform, in the pool in front of a metal-joining, do not disturb argon flow and not with the tungsten Xiangpeng.
(5) Welding dying, we should add more wire, and then slowly started to prevent the generation of arc pit.
(6) Welding finished, cut off power, must be within 3 ~ 5 s to send the protection of gas, tungsten and pool until slightly cooled the region, the unaspirated stop and avoid areas of Welding.
After testing five Welding
Welding colored surface after their inspection, the surface without any deficiencies. Welding after passing inspection
Department for manual grinding, grinding to meet the requirements, then Kim Sang fine sandpaper to throw. Welding the fine after throwing the metal color, luster, with the full -
Metal color, luster consistent, it can not see signs of Welding.
Conclusion
(1) using manual TIG welding, the left and right have Cover
Finishing the dry gas seal positioning Boss Department Welding, is the most
Welding the ideal method.
(2) the use of hand-TIG welding left and right to welding,
And from each other alternately to repair welding, welding without preheating, after welding
No heat treatment, Welding good effect, no deformation of the workpiece.
(3) high-pressure centrifugal compressor in the bucket in the case, in
On the left and right end of the dry gas seal with a convex targeting Taiwan into the Welding
Gong, ensuring product quality and delivery schedule
Centrifugal domestic refrigeration compressors that idea
Abstract: centrifugal refrigeration compressor characteristics, application conditions and trends; development of the difficulty of centrifugal compressor, the focus and countermeasures; development of the centrifugal compressor roughly steps.
Keyword: Centrifugal domestic refrigeration compressors
1. centrifugal refrigeration compressor characteristics.
Centrifugal refrigeration compressor as a speed-type compressors, has the following advantages:
(1) Cold in the same circumstances, particularly in the large-capacity, compared with the screw compressors, eliminating a huge oil installations, units of smaller size and weight, small footprint;
(2) Centrifugal compressor compact simple structure, movement of small, reliable, durable, low operating costs;
(3) Easy to implement multi-level compression and a variety of evaporation temperature, cooling easy to implement the middle, making lower power consumption;
(4) Centrifuges group mixes the oil is extremely small, the heat exchanger on the effect of smaller units with high efficiency.
Has the following shortcomings:
(1) Rotor speed higher, in order to guarantee a certain width impeller, must be used for large and medium-sized flow of occasions, not suitable for small flow occasions;
(2) Pressure than the low single-stage, in order to get a higher pressure than required to adopt the multi-stage impeller, but also with the general growth rate of gear;
(3) Surge is a centrifugal compressor inherent shortcomings of units required to add anti-surge systems;
(4) The same unit working conditions can not be a major change in the scope is narrow.
2. the centrifugal refrigeration compressor application conditions and trends.
The current domestic centrifugal chiller in most of Europe from Japan and the United States occupied by some refrigeration business. Well-known enterprises such as Trane, Kai-li, York, Maikeweier, AXIMA (original Sool Shou), EBARA original, Mitsubishi And so rely on advanced technology and good technology-led centrifugal chiller market. Domestic enterprises in Chongqing mainly generic, early introduction of the technology to develop NREC centrifugal chillers. With the development of society, users need more and more of the cold high, and because of Energy-saving requirements of the Group of centrifuges makes the market more widely. Number of domestic air-conditioning manufacturers such as Haier, Australia Kema, Geli and the United States (and Chongqing Universal Merger) have launched their own centrifugal chiller. AXIMA the cold and cooperative development Chu Lixin chiller and regional heating centrifugal heat pump units. Most of these centrifuges group of the use of environmentally friendly R134a.
With the growing tension in the form of energy, energy saving products development is a major trend. In addition the level of urbanization in China because of the continuous improvement, building energy consumption is increasing. With the highest coefficient of performance of the centrifugal chiller will no doubt be a hot market, In recent years centrifugal chiller sales continues to increase.
Most of the development of domestic enterprises centrifugal chiller compressor only buy imports, basically no profit. Centrifuges foreign manufacturers will not easily transfer their core technologies, to develop centrifugal refrigeration compressors, only walk the path of independent development. With Design and manufacturing technology continues to mature, making China the centrifugal refrigeration compressor developed possible.
3. developed and the difficulty of centrifugal compressor, the focus and countermeasures.
Development of a centrifugal compressor, including many of the elements: air heat, the intensity and vibration, structural design, materials selection, manufacturing process design, control and regulate the design and pattern-driven choice. Which The main emphasis of the difficulty in the following areas:
(1) Impeller Design
Centrifugal compressor rotor as the moving parts, the core part of the impeller. Centrifuges are the major domestic and foreign manufacturers have adopted methods of ternary flow impeller design. Ternary flow approach requires designers to have the numerical simulation, computational fluid dynamics, fluid Machinery, such as the internal flow of very specialized knowledge. Domestic companies do not have the technical staff most of these professional expertise, to design efficient ternary impeller, the only college and research institutions. Centrifugal compressor in the College of experts mainly in Shanghai National Chiao Tung University's Professor Gu-Gang, Xi'an Jiaotong University Professor Wang Shangjin. Professor Gu has long been engaged in the research centrifuges, has presided over six to complete the National Natural Science Foundation project, in ternary flow centrifuge design, compressor unit testing, monitoring and Control, anti-surge systems, such as in-depth study of all aspects, he presided over the completion of the "multi-stage centrifugal compressor aerodynamic design and application of technology" projects for 2004 national scientific and technological progress second prize. Leadership of Professor Wang Xian Jiaotong University Purcell Pump research group to a unique "controllable vortex impeller design theory", in the fields of petrochemical unit in the transformation of a good application.
(2) Impeller manufacture
Ternary flow to the design of the impeller blade shape for the general space surface, the impeller blade and the forming process is to create the focus is difficult. Impeller for three yuan, the processing methods commonly used mainly two kinds:
1) welding of three forms: That is roulette, leaves, round covered were processed. This method of processing equipment is relatively simple request, roulette, wheel covers only vehicles to form enough. Leaf processing it will take some work, The first to use 3-D milling machine to leaf mold, and then under the leaves of good material for heat treatment, the necessary pressure-leaf shape. Finally, the leaves of welding to the wheel, then covered welding good round. So in need of Equipment is probably the 3-D milling machine, heat treatment furnace, hydraulic machines and other equipment required for the conventional, the investment required is relatively low, more suited to start.
2) milling system as a whole: that is, roulette and leaves with the use of multi-axis milling equipment to the overall system and get a semi-open impeller. In order to avoid interference, the current international impeller on the processing of this large are using 5-axis machining Centre. A 5-axis equipment probably from several million to 10 million more than the cost was very high. Impeller to processing 600 mm for example, domestic bed about 5-axis to 3.5 million yuan, 5-axis bed probably have to import 4.8 million yuan. Through 4 Coordinates of the machine tool rotary table tilted to achieve the four ternary impeller milling coordinates the overall system, if the leaves more consistency, to interfere in the issue on the coordinates of the four is inevitable. Coordinates of the four devices are relatively cheap, probably more than 100 million yuan.
(3) Rotor critical speed of calculation
Speed is critical when the design of the rotor speed to be considered an important factor, the rotor speed to avoid the critical speed. Critical speed of calculation used Pu Luoer general, the market is critical speed of specialized computing software, can also develop their own calculation software.
(4) Antisurge system design
By the centrifugal compressor of the work we can see that surge is inherent in the nature of centrifuges, can not be eliminated, but can be an effective way to be avoided. Centrifugal refrigeration compressor surge in the reasons: low flows and high pressure condensate . Surge against the crew of a large, carefully designed to be anti-surge systems.
(5) Bearing Design
Centrifugal refrigeration compressors the general growth rate of gear, the rotor speed is generally in more than 5000 RPM, use plain bearings, sliding bearing centrifuge development of the design is also a priority.
4. developed and the centrifugal compressor general steps:
(1) Collect, study and centrifugal compressor centrifugal chiller and the relevant standards.
(2) Organization of the centrifugal compressor learn the basic knowledge to use one yuan-design theory compressor level.
(3) Organizing the personnel to the relevant scientific research institutes, manufacturers and professional study tour.
(4) In cooperation with research institutes ternary impeller design.
(5) The entire machine developed.
(6) Prototype test improvement.
5. the idea that
In the 1950s, Chinese scientists made Turbomachinery Professor Wu Zhonghua ternary flow theory, laid a ternary the theoretical basis for the design flow. Some foreign companies such as NREC this theory, such as the development of Chu Lixin impeller mechanical design and processing software .
China's scientists and technology workers have also carried out a large number of fruitful research, the centrifugal compressor design and processing carried out in-depth study and formed a series of research results, compared with foreign countries, no less. Recommendations Refrigeration domestic enterprises hold high the banner of national industries, developed a real sense of domestic centrifugal refrigeration compressor boutique
附錄B 漢語翻譯
筒型離心式壓縮機(jī)干氣密封定位凸臺(tái)的補(bǔ)焊
劉冬菊 哈福民 印明洋 黃維臣/沈陽鼓風(fēng)機(jī)(集團(tuán))有限公司
摘要:介紹了筒型離心式壓縮機(jī)干氣密封凸臺(tái)由于操作上造成的缺陷,從而進(jìn)行的補(bǔ)焊工藝。對(duì)補(bǔ)焊工藝方法的選擇作了比較,具體闡明了采用手工鎢極氬弧焊的補(bǔ)焊工藝方法,實(shí)踐證明,效果良好。
關(guān)鍵詞:離心式壓縮機(jī) 密封凸臺(tái) 補(bǔ)焊
中圖分類號(hào):TH452 文獻(xiàn)標(biāo)識(shí)碼:B
文章編號(hào):1006-8155(2006)04-0026-03
Rep air Welding of Allocating Convex for Dry Ga sSeal in Barrel Typ e Centrifugal Compre ssorAbstract:Repair welding technology of allocatingconvex for dry gas seal in barrel type cent rif ugalCompressor caused by operation fault is int ro2duced.The selections of repair welding technolo2gy are compared,and t he repair welding technol2ogy using handwork gas t ungsten arc welding isdetailed.The result wit h good effect is got.Key words:Cent rif ugal Compressor Seal convexRepair welding
1.引言
在組裝某臺(tái)筒型壓縮機(jī)干氣密封時(shí),發(fā)現(xiàn)在左、右端蓋上安裝干氣密封處,所鉆的一次排氣孔鉆到干氣密封定位凸臺(tái)處,使密封凸臺(tái)破壞,破壞面達(dá)25mm×10mm×7mm(見圖1中的F向),造成干氣密封定位膠環(huán)局部密封不好。
左、右端蓋本身做水壓試驗(yàn),壓力為30M Pa,合格后端蓋與機(jī)殼同時(shí)做氣壓試驗(yàn),壓力為20MPa,介質(zhì)為氦氣。該產(chǎn)品的氣體介質(zhì)為循環(huán)氫,承受工作壓力16 MPa;如果密封凸臺(tái)不補(bǔ)焊,不僅影響外觀質(zhì)量,更重要的是在機(jī)組運(yùn)轉(zhuǎn)時(shí)將會(huì)造成密封漏氣,嚴(yán)重時(shí)還會(huì)影響干氣密封的使用,從而導(dǎo)致工藝流程癱瘓和機(jī)組停機(jī),后果不堪設(shè)想。
左、右端蓋材質(zhì)為KMN材料,該材料特殊,補(bǔ)焊難度非常大,由于左、右端蓋已精加工,如果補(bǔ)焊措施不當(dāng)會(huì)引起裂紋,焊后變形,最為嚴(yán)重的是導(dǎo)致該部件報(bào)廢。
圖1 端蓋補(bǔ)焊區(qū)域圖
2.KMN材料簡介
KMN材料是我公司離心式壓縮機(jī)焊接葉輪、端蓋等專用材料。該材料為鉻鉬合金,焊前需要預(yù)熱,焊后需要熱處理,在調(diào)質(zhì)狀態(tài)下使用,焊接工藝復(fù)雜,焊接時(shí)用KMN材料的專用焊條。
3.補(bǔ)焊方法選擇
3.1 激光冷焊
由于左、右端蓋已經(jīng)精加工,干氣密封定位臺(tái)也已加工完畢,焊接熱輸入量會(huì)導(dǎo)致焊后變形。為防止焊后變形,焊接方法首選是冷焊。為了保證補(bǔ)焊質(zhì)量,筆者與中國科學(xué)院金屬研究所激光表面熔合的專業(yè)技術(shù)人員,進(jìn)行了現(xiàn)場質(zhì)量分析,確認(rèn)是否可以采用冷焊的方法進(jìn)行補(bǔ)焊。激光表面熔合焊的技術(shù)人員對(duì)端蓋KMN材料的性能、可焊性等,都感到陌生,補(bǔ)焊的位置處于端蓋的中間處,確認(rèn)在補(bǔ)焊時(shí)電極接觸很困難,即使電極接觸到焊接效率也極低,質(zhì)量又很難保證,面對(duì)此種情況,確認(rèn)不宜采用激光冷焊。
3.2 手工電弧焊
采用手工電弧焊進(jìn)行補(bǔ)焊,靈活方便。由于KMN材料是公司專用材料,也有專用KMN焊條,焊接材料和焊后性能都沒問題。關(guān)鍵是需補(bǔ)焊的左、右端蓋的位置都是在精加工后的干氣密封區(qū)域,補(bǔ)焊時(shí)需要焊前預(yù)熱,焊后熱處理,手工電弧焊的熱輸入量很大,都會(huì)增加補(bǔ)焊區(qū)域的熱輸入量,熱輸入量的不斷加大,將會(huì)導(dǎo)致焊后變形。如果產(chǎn)生變形,
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