Journal of Welding Science and Technology of Iran
نشریه علوم و فناوری جوشکاری ایران
JWSTI
Engineering & Technology
http://jwsti.iut.ac.ir
1
admin
2476-583X
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fa
jalali
1396
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gregorian
2018
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اندازه گیری تنش پسماند در جوشکاریTIG فولاد زنگ نزن 304 به روش آلتراسونیک
Measuring of Residual Stress in TIG Welding of the 304 Stainless Steel by Ultrasonic Method
تخصصي
Special
پژوهشي
Research
<span style="font-family:b zar;"><span style="font-size:12.0pt;">در این پروژه برای اندازه گیری تنش پس ماند جوش فولاد زنگ نزن </span></span><span dir="LTR">AISI 304</span><span style="font-family:b zar;"><span style="font-size:12.0pt;">از روش اندازه­گیری موج طولی شکست یافته بحرانی و همچنین روش سوراخ کاری استفاده شده است. به این منظور پارامترهای جریان پالس، جریان زمینه، درصد زمان پالس و فرکانس پالس به عنوان پارامترهای متغییر در نظر گرفته شده و از طراحی آزمایش تاگوچی</span></span><span dir="LTR">L<sub>9</sub></span><span style="font-family:b zar;"><span style="font-size:12.0pt;"> استفاده شد. هرکدام از نمونه ها مورد آزمون کشش و سختی سنجی و همچنین بررسی ریز ساختار قرار گرفتند. نتایج نشان میدهد که جریان زمینه موثرترین پارامتر در تنش­های پس­ماند بوده و جریان پالس عامل مهم بعدی و درصد زمان پالس و فرکانس پالس در اولویت های بعدی قرار دارند. </span></span>
<img alt="" height="2" src="file:///C:UsersuserAppDataLocalTempmsohtmlclip1�1clip_image001.gif" width="315" >In this research, the effect of different welding parameters on residual stress and microstructure of the weld region, as well as the comparison of two methods of measuring residual stress using critical fracture longitudinal wave method and preformation method have been investigated. For this purpose, the taguchi DOE methodology is used as a statistical method to optimize four parameters of pulse current, base current, and pulse on time% and pulse frequency to minimize longitudinal residual stresses in austenite 304 AISI stainless steel. After welding, stress measurements were performed using two methods critical fracture longitudinal and perforation, and hardness, tensile and OM tests were performed on the specimens. The tests results show that at all levels of the pulse parameters arranged with the standard L9 Taguchi array, the incident heat input is irrefutable and the effect of this parameter is move then 50%. The optimum conditions obtained while the highest frequency level should be considered. The general trend is achieved from the residual stress measurement charts is consistent with the logic of stress distribution in both methods. Sample number 1 with stress equivalent to 232 MPa and sample number 9 with stress of MPa 126 in ultrasonic method with frequency 4 MHz have the highest and lowest stress among different samples, respectively. The size of the coaxial grains weld was directly related to the incoming heat, so that the least amount of coaxial grains in the welding center was related to specimens NO. 3 and 9 with grain size of 8 µm and 9 µm, which in these samples had the lowest amount of welding heat is measured. The samples 1 and 4 with HV 128 and HV 144 hardness and MPa 633 and MPa 639 have the least hardness and tensile strength and the highest strength and hardness of sampled 3 and 9 with 166 and 161 hardness and tensile strength MPa 703 and MPa 695.<br>
تنش پس ماند, سوراخ کاری,آلتراسونیک, فولاد زنگ نزنAISI 304 , رشد ستونی.
Residual Stress, Critical Failure Longitudinal Wave Method, Variance Analysis, , TIG Welding, Austenitic Stainless Steel.
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32
http://jwsti.iut.ac.ir/browse.php?a_code=A-10-132-2&slc_lang=fa&sid=1
A.
Parvaresh
آرش
پرورش
10031947532846001177
10031947532846001177
No
Department of Materials Engineering, Karaj Branch, Islamic Azad University, Karaj, Iran.
H.
Sabet
حامد
ثابت
10031947532846001178
10031947532846001178
Yes
Department of Materials Engineering, Karaj Branch, Islamic Azad University, Karaj, Iran.
M.
Roohnia
مهران
روح نیا
10031947532846001179
10031947532846001179
No
Department of Wood and Paper Science and Technology, Karaj Branch, Islamic Azad University, Karaj, Iran.