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nvestigation on Fatigue Strength of Aluminum Alloy 606-T6 Resistance Spot Welded Going under Tensile-Shear test D. Afshari Faculty of Engineering, University of Zanjan, Zanjan, Iran F. Sardarzadeh Faculty of Engineering, University of Zanjan, Zanjan, Iran N. Noorafshan Faculty of Engineering, University of Zanjan, Zanjan, Iran Abstract Resistance spot welding(rsw) is one of the most popular welding methods in joining sheet metals of cars, and etc. In RSW process, a high electric current is passed throw two sheets via electrodes, which results in the generation of a melting zone between the sheets, called nugget. The main purpose of this study is experimental investigation on static and fatigue strength of aluminum alloy 606-T6 with 2 mm thickness. To achieve this goal, many samples were prepared and welded by different RSW s parameters. The mechanical strength of welded samples was examined under tensile-shear test. The results show that, by increasing the nugget size, the static strength is improved. In addition, however at first, the fatigue strength is increased by improving the nugget size; it s decreased significantly after a certain nugget diameter. The micro-structural study indicates the formation of cracks in the HAZ after the certain nugget diameter. However, these liquation cracks have no effect on the static strength of spot welded samples; they cause dramatically changes in the fatigue strength of samples. Keywords: Resistance Spot Weld, Fatigue Strength, Static Strength, Nugget size, Tensile-Shear Test. 5000 2000 ;8 -C 6, C / 8 F, :8 :8 > (@ ; 7.[] 5 7, 6 :? (@ P> C 8 JU 7 8 64 8 S e? A ).> )- S 8 C b ^ PQ W^ fh: 7 8 AB= 8 8,.@ 6 :? (@ 6 YJ= H :8.58 64 8 J> 6 GHI J- 98 8 J? :8 6 :? (@ AB F,, 8 6 YJ= 8 3 (@ J- :O PQ (@ 8 6> b 6 8 GHI 6>, ; 88. - AB / ABZ 4 2Ja 6 8 (@ J- :O J GHI Ig :O 8 4 T >., 5 ^ fh: 7 8 AB 3-.O AB 6.5 ; 8 4 6 :?? (@ <U 2, H8O <3.,\8 U,.58 GHI 6QH AB H8O ] Z 6\8 Q J 8 4 > J.58 6 :?? (@ ]^BC ; J.4 W^ 2 65@ ; 84. > _ 6> 4, >J> >:O 64,C64,? H98 > ` a 4 2 @ U ; Z ; PQ 8 3 b AB Z AJU 2 8 2QJ> (@ J- 3. - (@ J- Y. - (@ J- b AB 8 3 > F, * dafshari@znu.ac.ir : 95/02/9 :! 95/07/03 :( )!
<=k, k4 2 68 ]9: 5 5 :J> 7k, k Vk, k - ]k^ 6\k GkHI 6>D 0C kj k 6>D 6 :? (@ AB ; 9: PQk 8 C 6., @ ; T >., - O @ k. PQk 8 64, C W^ >D ; 4 7, YJ Pk S 200 A, [9] PJ> Z At 298., k8 5083 <k Dk 0kC <=k, 6 k8 Jk 6> ;knj>.k ko k9: = 2J ( 4 7,!k, ( 4 7k, k8 [0] PJ> 2C u Y_ 202 A, 606 <k Dk 6 :? (@ AB <=, X:,. J 8 P 5 8-8 = (k@ AkB <=k, k4 k - ]k^ ]k9: k 0kC k, <=k, 7 > > 2 6 :?.k58 k )- S 8 5 6 (@ 4, 7 AB 24 7 ;, 8, 5 9, Q 9: ; ko 9: 606-T6 < 6 :? (@ AB 6 8 5 8 (k@ kj- k:o ;8k k:8 k, k5 (vk ;knj>. - kk ;k8. k- ko k, 8 k 0C, <=, 6 k:? (k@ F, 5 65@ 6> J 4 6 UJ3 k, 8 k8 GHI 8 3 6> 244 7, 8 5? k k.8 [ 6 k8 ;knj>.k, k5 kc k> k ;., - O, 8 J > W:? X:, > J 0C ('. 5C 8-2 b 4 6 k:? (k@ AB <=,, 8 6 8 9: ;.k, 5 7, H 2 Ig 8 606-T6 < D Cr 0/., 5 w 7, D J5 h 606-T6 6 78 978 F G>'. -,4 Cu 0/2 Fe 0/5 Mn 0/ Mg /0 Si Al 97 6\8 A@ J5 BU 4 ^ Hk,8 kj k> (k@ Yk= k8 > J 65@ 6 8 ;k5 4 7k, k8 65@ rl, 5 4, Fkk,200 kava kk 2kk kk8 PMP DGS Akk NIMAK Yk5 k5 6> J 98., 5 <3 6> 0/6., 5 PJ ' (?I(/) 5 5C?I(/-H ( ( f) P5 <U 8. @ T h: (@ J-., 5 ^ 6:? (@ ;Z 6 :? (@ AB F,, YJ= i e. 8 6> 7 4 0 (@ AB 0C <=, 4 68 6, C / J>.58 AB 7 ;9 j 9 6 :? (@ F, 5 65@ 6> 4, 4 AB 0C <=, ).58 J 6>8 4 6> 4, Z a, 6 g 6> e.,5 - O K 8 JU H8O J K e. 8? (@ ]\B 0C <=, S YU 2 6 :? (@ AB 0C <=, 9: ; 4.58., - O 68 ;??= @ Jk 6> P S, 8 82007 A, [2] PJ> 0\ b 6 k:? (k@ lk, 6> Y5 m 6 8 0C 6k> P5 4 7, 8 [3] PJ> n. C 6\ k k= 2kJ Ak /k 4 7, 8 P 8 8 6C, k \k8 <=k, k8 6\ 6> b 6 :? (@ 0C ek, 6 k8 ( ;k 4 2k k 2 O 9: 2008 Ak, [4]QJk, (k. 7, JU -<=, = k9: 0C <=, 6 8 6 :? (@ 6> S kju k= 2kJ ( 4 7k, 8 [5] n5 n. O AkB Z I, W4, 8 6 :? (@ AB 0C /k [6] 2-k ;k ;knj>.k ko k8 P 7k, k8 B 6> 6)-8 0C JU 0 9: 9 k5.k ko k8 Pk 9a r ] m 4 /k 6 k:? (k@ 0kC <=k, 200 A, [7] 8 m 2 k. 6-4 5 8-24 H,8 6\ b k8 Jk 6k> Pk ks ; k- kk 8 Q [8] =^ k5 6 :? (@ 0C JU [ ( - ( 4 7,. J 64, k 8 > 64, C W^ ]QH ;8 4 kj> Dk rk@ fi 6 8,, BI / 2U 8 24 8k, 64k, C _.k58 k k,, Yk^ /k \8 <=, RkC Yk k8 k> - > W^. - O @ kqh /, 24 8 6> 4, 8 HJ@4 e ]7 6>D k O 7k, k> 6k> 4, 2, 4 8 B= 7k, k k ; H^ 4 >D ; Q 2 e>. - Qk 64k, kc Wk^.k58 _ > 6> 4, 4 k> GkHI 6k>C < 6>D 4 7, YJ kh98 <k 6k>D 6 :?5@ T -.58 PQ AZ k ;k k Vk58 k \k 4 Y 2 s Z RC Wk^ k 6k> b AkB ( ; k8 2kNJ>.58 GHI... D? 6:? (@ AB 0C, 8 kj- k:o k8 AkB k <=k, :8, 8 <Q 8 @ 8 (k@ kj- GkHI 6> :O 8 5 65@ 6> J (@ Mesh-intensive structural stress approach 2 Tensile-Shear test 50
2 H 4, x 6.k k5 } (.70ml 60ml HN 0ml HF) Jk5 AH= 4 Pk 2 k /kc k5 k> kj 64, HZ.58 6l, 4 7, 8 C, Q 9: NF-3 J- :O 8 AB 0C, <=, :8, 8.@.@ 65@ GHI 6> 8 > J 65@ 8 4 (@ <4\ kk ;k8.k58 k (@ J ]7 6> :O 8 8, kh 2 Ig 8 b 6 8 (@ J- :O 8 J,, 8 (@ J- :O J fi 9: ;.5 ;9 6 k kh2 Ikg 8 6> b 6 8 [] AWS, ^ k:o k8 fki ;knj>., 5 - K H 5/7 65@ f) P5 4 f@ 8 @ 8 Q (@ J-.[2], 5 ;9 H 8/5 GkHI 6> (@ J- :O AO Y8O = 8 @ 8 k - kk (k@ J- 6> :O 8 8,.@ 6 :? (@ <k3 4 k98 k5 6k5@ kj k>. - O, 8 5 6 k- 4k (@ J- :O 5 8 AB Y= 4 (@ k.@ 6 k:? (k@ 6k> ]kuva ; 6 8, 5 7 2k.k, k5 X=B K (@ J- :O 8 8, 6 k8 6 k:? (k@ GHI 6> 8 5 65@ J 6, AkJU (@ 6> 2 A@. 5 fi 9: ;, 8 kw (k@ kj :O 4 8 J> > J 4 6, > 6 8 5., C. 5/'(,O/ 5/ 23 0 5C'/-2,4 (@ J- :O (mm) 5/72 5/95 6/42 7/06 7/49 7/98 8/4 (@ 24 (ms) 60 40 2 @ ]5 (ka) 36 39 37 38 39 40 37 6, 2 3 4 5 6 7 GHI 6> 2= 8 8 K ;8.8 4 9: ; k5 6 k- 4k GkHI 6k> J (@ J- 98 65@ 6k yk, /k 4 7k, k8 (@ J- :O 6-4. kj > K ;8., 5 <3 6 l e, / 8 YB 4 rk k5 k 8 AB Y= 4 6 :? (@ <3 4 98 kj- 2 Yk5.k, k5 6 k- 4 (@ J- :O 64,.> PJ 5 65@ J / (@ L4 4?,-./ M? 0 >?-2H 2k4 ;k5 4 7, 8 > J (@ J- :O 25 zi 8 k8 k5 8-k, 6)-8 = J > (3 kj k> k, <=k, k - O mm/min Y5) 8S U, 6 k- 4k k9: ;k ;NJ>.k - ko 6 k- 4 ]k^ k5 8-k 6)k-8 = Q J > 0C <=, 2500 2000 500 000 6k>8 4 K ; 6 8., - (R=0) 7k^ 6)k-8 k8s k 0 HzJk8 k8., 5 7, 5 2 A@ 5 w 6> J J 6 8, ~ 8 <4\ 20 ; 4000 h 8 8S (@ P 24 6 4 6, > 6 8 9: ;., 5 - K S H - J 9 2 J5 A@ 5 w (@ 6> AB 0C, <=,, 8 6 8 J 63 J3., - O, 8 (@ (k@ kj- :O 5 65@ 6> J 25 zi 4 r -k 2k4 6 8 J 4 6, > 4 J 3 > J 4 6, > ko 6 k- 4k > J, <=, ;9.@ 5 8 k:o (k@ AkB, <=, 2 :8 4 Y5. - YkJ= 8 ; 8, ~ 8 <4\.> PJ (@ J- k5 YkJ= k8 ; k8 ;0 8 8 4 Y5 5 w 5?8 5C '( ==> 8-3H 6k> kj 0kC k 4 k.8 [ 6 k8 k9: ;k yk, /k 4 7k, k8 kj > W:? X:, V5 65@ 6k5@ 4 rk kk ;k8.k, - O 9: 6 k 4 7k, k8 5 3 AB Z 5 8 J > AB 6k> J. 5 y, 4 9: 6 8 > J < - /k 4 7, 8 rl, 5 P HZ ;T a 5
k> 6 k8 k5 2k4 kj 3 AB 5 4 P (@ AB.58 > J 4 6,... D? 6:? (@ AB, 8 0C 5 5C *+ 'O /?-6H 8 8 PQ 8, zi 6 J5 Y5 :J> P> > J 4 6, > 6 8 0C JU 5 65@ J 0C JU = ]7 >J ; e.., > J, 8 H 8/4 7/98 :O 8 > J AB H 7/49 8 H 5/72 4 (@ J- :O PQ 8.58 5 (@ 6> J 0C <=,, <=, 0C JU P> > J 4 6, ; 6 8., PQ 6 8.58 = 8 500 8 000 8 6 8 000 8 6 8 AB 0C JU Z > J 4 6, ; JU 500 8 6 8 58 2H = ;.,?, 20 5 = 8 (@ AB 0C 8 2000 8 2? 0C JU P> 0JT > J 0C JU Z.5 > Q 2500 2500 8 6 8 O 0 5 = 2000 8 =., 0 4 = 8 (@ AB 0C JU 3 8 PQ Q H 8/4 7/98 :O 8 6> J 6 8 6k> JU k.k, k5 6 :? (@ AB 0C JU P> 8 kj 4 ]k7 Y :8 > J 6, ; 6 8 5 S 0C k8 H 7/49 4 (@ J :O PQ 8.58 ; 6> <=k, (k@ AkB k, <=, vc 8 H 7/98 0C JU Z., P> ]5 8 AB 0C Vk58 k 230050 k 000 k8 k= 7/49 k k P>k 2258 k8? ; 7/98 8 :O 8 J :O 8 J 6 8 6)-8 J 5 65@ J 0C JU P> ;., >k Qk 6 k kh 8/4 kh 8/4 k8 k H.5 > > k:o k8 kj ; K 7/98 4 (@ J :O PQ 8.5 kju 2k?., 0C JU P> kj 6 k8 k k> k 2 GHI 6> 6)-8 = 0C J 6 H 8/4 :O 8 J 0C JU 5 AJU 6>8.58 6 H 7/98 :O 8 J 0C JU 4,-././ 6"/ 40 ;? '2P 2(/ /?-4H <=k, 2 J? :8 V, zi Y5 ; :J> k@ > J 4 6, > (@ J :O (@ AB, kj Fk, k5 YJ= 8 ; 8 (@ J :O PQ 8. 2k4 ;k.k, k k PQ (@ AB ;5 4 P kj 6 k8 ;k 32 (k@ AB F, 5 YJ= 8 ; J 4750 k5 YkJ= k8 ; k8 ( k kh 5/7) (@ J- :O k5 ks ( kjh 8/4) (k@ kj k:o k8 6 k8 ;k Yk= 4 6 k:? (k@ AkB 5 24 ; e.., k8 ; k8 PQk k@ k8.k58 k > J J 6 8 (@ k-q8 (k@ kj k:o 8 6> J 6 8 AB F, 5 YJ=.(5 Y5) - > > J 5 ;. 2NJ> kj 6 :? (@ AB, <=, 6-4 4 r ko 7k, 0C <=, 6-4.@ O8 6> <=k, 2k4 k kj 42 kj3 k9: ;k. - k, 8 6 k8 k5 6k5@ kj 28 4.k, - O 0C ;k 2500 2000 500 000 6k>8 k= 0C <=,.8? 6 8 2000 8 = 0C 24 5 7, Y5., 5 8 3 > J 4 6, > 0C <=, 2 k> kj 4 6 k, k> 6 8 0C 24 4 Y^Z J 6 J5 k= 6k> kj kh 6 k8 k k, ~ 8 <4\., PJ ;8 ]B8 > J AB Y= 4 5. Q 0C 6)-8. - > 6 =7^,-./ M / 5 5C <-5H 52
2 H 4, x 6 ((@ J :O PQ ) AB Z 8 6 6 - PQ 8,., PQ Q (@ J a < - 6> [ k5 8-k 2k4 = 5 65@ 6> J, 8 <=k, k8 6 Sk HAZ kz 6k> [ @ > 2 (k@ AB 3 ; 8. 6 :? (@ AB, kz ;.[4], 5 > Q 64 6>\ 6 :? <=, = 8 3 7 6 6> J. ; @ YkU k k> k 2k, 5 6 :? (@ AB 0C.k58 k 6 k:? (k@ AkB 0C <=, J. 8 kj k8 7 J > [ ; PQ > 2 M., 5 Q (@ AB 0C <=, 8 P> 8 3 6 4 6 kk, kk> 6 kk8 0kkC kkju 2kk kk? 7 Jkk5 Ykk5 kju k k, k~ k8 <4\.58 2000 J 3 8 = > J 0C JU ;0 J ; 5 2 0C (@ AB 0C 7 J5 Y5.58 > J4 6, > Z. 6 k k H 7/49 8 H J5 Y5 5 PJ 6 :? 5/72 4 (@ J- :O PQ 8 k5 (k@ 6k> kj 0kC <=k, k, <=, 8 H 7/49 4 (@ J :O PQ 8 V, PQ <=k, (k@ AkB k, <=, vc 8 H 7/98 k8 kj 6 8 > ;, P> AB 0C.58 > Y8O Q H 8/4 X:k, k5 6k5@ 6k> J 0C.8 [ 6 8 k~ k8 <4\.k - ko k, 8 AB Z > J W:? 6k5@ 6k> kj kj 6 8 > J X:,, 8, k.k, k >k AkB :O ka =:k, [ M> 5 6k> J 6 8 T > > 2 (@ W:? X:,, 8 7 6 6k> kj 6 k8 V @ AB Z > 5 >k (HAZ) k S = Z > [ (@ J a 7 6 6k> kj (k@ Wk:? X:k, kb 8 Y5.5 8 Yk5 k (k@ kj- ka 6. WO.> PJ k kc- 6k. 8 < - 6. 4 5 2.5 (G) 53 (f) 6 :U7/ 0 ;? R/'S/? 6'; 5C T'. -8H 7 :V 5 ( W-4 6 k:? (@ AB 0C, <=, 9: ; k, 8 k k H 2Ig 8 606-T6 < D? k <=k, (@ J- :O 2 :8 ;NJ>. - O ;k 4 k k,8 Mk.k, k5 k9: 6 k:? (@ AB <=k, k8 J? S (@ J :O > 2 9: PQk k8 k3 2 PQk 6 :?k5@ AkB k,. - JB, <=, <=k, PQk k8 k3 (k@ k:o J PQ T > (k@ AkB 0C <=, 6 8 V - (@ AB, k k> k 2k 9: ; M. b^ Q- ; 6 :? k:o PQ H 2 Ig 8 606-T6 < D b 6 8 0kC <=, P> 8 3 H 7/5 4 P8 8 (@ J.2000( <". 5 5C *+ 'O-7H ;kz AB Z 8 5 6 - PQ 8, K 8 AkJZ (k@ kj- k:o PQk 3 6 :? (@ ; - ]^ ]9:., PQ > [ ; 3 kz 8 5-6D 2Q 2 Q [4 ]k9: ;k.k58 k. k ; 3 3] ; J. AB 6 kz 6 :? (@ ;Z. ; 2 k hk@.5 Y, f~ Y :8 kj- 2 k8 k8 k. ( k- k. 2? 4 > [ ; zik Qk 8 Liquation crack Y5 :J>.58 b 6, (@
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