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ÖZET Çelik malzemelerin kaynaklı bağlantılarını EN 25817 ve TS 7830 standartları ile daha kolay değerlendirmek amacıyla bu tez çalışması yapılmıştır. Kaynak bağlantılarının değerlendirme işleminin daha kolay yapılabilmesi için QBASIC programlama dili ile her iki standart için ayrı ayrı birer bilgisayar programı yazılmıştır. EN 25817 ve TS 8730 standartları için hazırlanmış olan bu programlar iki bölümden oluşmaktadır. Programın birinci bölümünde kaynak hatalarının sınır değerleri aranmaktadır, ikinci bölümde ise, kaynak bağlantısının yapılan muayenesi sonucu elde edilen hata değerleri programa yazılarak kaynak hatasının kalite grubu tesbit edilmektedir. Tez çalışmasının l.bölümünde EN 25817 ve TS 7830 standartları hakkında bilgi verilmiştir. Ayrıca programların esasını teşkil eden bu standartlar tablolar halinde sunulmuştur. 2. bölümde ise, programların yazıldığı QBASIC program dili hakkında açıklamalar yapılmıştır. Daha sonra EN 25817 ve TS 7830 ile ilgili bilgisayar programlarının nasıl yazıldığı ve kullanıldığı açıklanmıştır. Sonuç olarak EN 25817 ve TS 7830 ile ilgili yazılmış olan bilgisayar programlan amaca uygun olarak çalışmaktadırlar. vuı SUMMARY The thesis includes a QBASIC program which is used to evaluate the arc - welded joints in steel according to EN 25817 and TS 7830 standards. In the first section of the thesis you will find information about EN 25817 and TS 7830 standards. In addition you will see tables that include limits for imperfections. In the second section of the thesis you will find information about QBASIC program. In addition you will see how the program is written and how it works. 1. The Standard EN 25817 This international standard should be used as a reference in the drafting of application codes and/or other standards. It may be used within a total quality system for the production of satisfactory welded joints. It provides three sets of dimensional values from which a selection can be made for a particular application. The quality level necessary in each case should be defined by the application standard or the responsible designer in conjunction with the manufacturer, user and/or other parties concerned. The level shall be prscribed before the start of production, preferably at the inguiry or border stage. For special purposes, additional details may need to be prescribed. The quality levels given in this Standard are intended to provide basic reference data and are not specifically related to any particular application. They refer to the types of welded joints in a fabrication and not to the complete product or component itself. It is possible, therefore, for different quality levels to be applied to individual welded joints in the same product or component. Quality levels are listed in table 1. Table 1 - Quality levels for weld imperfections IXThe three quality levels are arbitrarily identified as D, C, B and are intended to cover the majority of practicable applications. It would normally be hoped that for a particular welded joint the dimensional limits for imperfections could all be covered by specifying one quality level. In some cases, however, e.g. for certain type of steels and structures as well as for fatigue loading or leak tightness applications, it may be necessary to specify different quality levels for different imperfections in the same welded joint or to include additional requirements. The choice of quality level for any application should take account of design considerations prior processing, i.e. surfacing, mode of stressing, service conditions, and consequences of failure. Economical factors are also important and should include not only the cost of welding but also that of inspection, test and repair. This standard does not include details of recommended methods of detections and sizing and, therefore, it needs to be supplemented by requirements for exemination, inspection and testing. It should be appreciated that methods of non-destructive examination may not be able to give the detection, characterization and sizing necessary for use within certain types of imperfection shown in table 1. 1.1. Scope This Standard provides guidance on levels of imperfections in arc-welded joints in steel. Three levels are given in such a way as to permit application for a wide range of welded fabrications. The levels refer to production quality and not to the fitness-for- purpose of the product manufactured. This Standard applies to - unalloyed and alloyed steels; - the following welding processes and their defined sub-processes in accordence with ISO 4063: 1 1 metal-arc welding without gas protection; 12 submerged-arc welding; 13 gas-shielded metal-arc welding; 14 gas-shielded welding with non-consumeable electrode; 15 plasma arc welding; - manuel, mechanized and automatic process; - all welding positions; - butt welds, fillet welds and branch connections; - materials in the thickness range 3 mm to 63 mm. When significant deviations from the joint gemeotries and dimensions described in this standard are present in the welded product, it is necessary to evaluate to what extent the provisions of this standard can apply.2. The Standard TS 7830. This standard is most used standard by evaluating the welded joints. The Standard TS 7830 are a Turkish standard that was translated from the DIN 8563 standard. In this standard the imperfections were classified according to testing and inspection methods. TS 7830 include necessary properties for quality guarantee by butt welded and fillet welded joints in steel 2.1. Scope This standard is used for classify the quality groups for butt welded and fillet welded joints in steel. 2.2. Quality levels for the standard TS 7830 The external and internal properties of welding were graded and classified to quality groups for welded joints request. Quality groups are graded from high to low request. Quality groups are listed in table 2. Table 2. - Quality groups for the standard TS 7830 2.3. Imperfection designation of the standard TS 7830 Imperfections are grouped as internal and external imperfections External imperfections - Excess weld metal - Incompletely filled groove - Linear rnisalignment - Excessive asymmetri filled welds - Undercut - Crater - Cavities on surface - Spatter - Starting the arc - Root concav - Lack of fusion on the root - Root notch Internal imperfections - Blowhole XISolid inclusions Lack of fussion Lack of penetration Cracks Crater cavities Lack of penetration filled weld 3. QBASIC Program QBASIC programs are created with specified rules and terms. To create programs it is needed an natural environment. Therefore it is used QBASIC editor. QBASIC editors is a `full page` editor. This means program's lines can be seen all time on the editor, and the cursor can move in all direction freely. Furthermore using mouse makes program writing easy. QBASIC.EXE is a file in the MS-DOS directory. QBASIC is not a compiler. It is a commentator. All written lines are respectively translated in machine language and processed. Therefore it works slower than a compiler. To work on the QBASIC editor it should be written C> QBASIC in the MS-DOS directory and press the key ENTER. After all these the QBASIC editor will be reached. 3. 1 Writing a QBASIC program The program must be written on a clear screen. QBASIC programs are written in free style. Program lines must not be numbered. In spite of numbering the lines the program will work. Before writing a program the problem should be systematic investigated and its all details should be determined. After analysing the problem flow chart can be written. According to the flow chart program lines are written. Then the program is runned, mistakes are determined and eliminated. 4. Using En 25817 and TS 7830 standards with a program A program was created to evaluate welded joints easier by using EN 25817 and T S 7830 standards. QBASIC was used to write program. 4. 1. Program about the standard EN 25817 This program is created to evaluate welded joints in steel by using QBASIC program. The program about EN 25817 is written to look for imperfection levels in quality groups. In addition it is used to determine the quality groups according to imperfection levels. xn4. 1. 1. Writing of the program First the problem was analysed. Then principles of writing were determined. According to these it was decided that the program should contain two subprograms which were explained above. Then it was prepared a flow chart for the program. According the flow chart program lines were written in order. Finally the program ran and all mistakes were eliminated. 4. 1.2. The flow chart of the program Flow chart is used to show the processes of the program in a scheme. It is arranged to write the program easier and without mistakes. The flow chart of the program is shown in figure 1. (start Cycle CSTQp Of RUN Subprogram 2 Figure 1- Flow chart of the program xni4. 1.3. Running the program To run the program you should write C > QBASIC in MS-DOS directory to reach the QBASIC editor. Then press the key `F5`. In other way to run the program you should write C > QBASIC / RUN EN_25817 in MS-DOS directory. After doing one these processes the program will run. 4.2. Program about the standars 7830 This program is similar to the program EN 25817. It is written in the same order as the program above explained. To run the program you should write C > QBASIC / RUN TS_7830 in the MS-DOS directory. You can see both programs in appendix. xiv 79