ÓBUDAI EGYETEM BÁNKI DONÁT GÉPÉSZ ÉS BIZTONSÁGTECHNIKAI MÉRNÖKI KAR

ÓBUDAI EGYETEM BÁNKI DONÁT GÉPÉSZ ÉS BIZTONSÁGTECHNIKAI MÉRNÖKI KAR

International Engineering Symposium at Bánki IESB 2014 Nemzetközi Gépész és Biztonságtechnikai Szimpózium 2014. november 20.

A MAGYAR TUDOMÁNY ÜNNEPE TISZTELETÉRE

ANYAGTECHNOLÓGIA SZEKCIÓ Elnök: Rácz Pál Danyi József1 – Végvári Ferenc1 - Béres Gábor1 – Kecskés Bertalan2 1Kecskeméti Főiskola GAMF Kar, 2HILTI Szerszám Kft. EXAMINATION OF DEEP-DRAWABILITY OF LASER WELDED BLANKS Lendvai László BME Polimertechnikai Tanszék EFFECTS OF MICROCELLULOSE/LAYERED SILICATE REINFORCEMENT ON STARCH-BASED COMPOSITES Czinege Imre – Csizmazia Ferencné- Zsoldos Ibolya Széchenyi István Egyetem, Anyagtudományi és Technológiai Tanszék LASER WELDING OF STEEL -ALUMINUM SHEETS Danyi József1 – Végvári Ferenc1 - Béres Gábor1 – Kecskés Bertalan2 1Kecskeméti Főiskola GAMF Kar, 2HILTI Szerszám Kft. TUBE EXPANSION WITH POLYURETHANE MEDIUM Csóré András – Szabó J. Péter BME Anyagtudomány és Technológia Tanszék DETERMINATION OF DISLOCATION DENSITY IN METALLIC CUBIC SYSTEMS WITH ELECTRON BACKSCATTERING DIFFRACTION Gáspár Marcell – Balogh András Miskolci Egyetem Mechanikai Technológiai Intézeti Tanszék EFFECT OF t8.5/5 COOLING TIME ON THE CRITICAL HAZ AREAS OF HIGH STRENGTH STEEL JOINTS Dugár Zsolt1 – Béres Gábor1 - Kis Dávid István1 – Antalicz Gergely2 1Kecskeméti Főiskola GAMF Kar, 2HILTI Szerszám Kft. DETERMINATION OF RECRYSTALLIZATION TEMPERATURE OF VARYING DEGREES FORMED ALUMINIUM, BY DMTA TECHNIQUE

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Institute of Materials Science and Technolog

University of Miskolc



Content

International Engineerin ng Symposium at Bánki

EFFECT OF t8.5/5 COOLING TIME E ON THE CRITICAL HAZ AREAS OF HIGH STRENGTH ST TEEL WELDED JOINTS ME

• • • • • •

Definition and grouping of high streng gth steels Welding difficulties of Q+T high streng gth steels Critical HAZ areas in single and multipass welds Simulation of critical HAZ areas by GLEEBLE 3500 physical simulator Material tests Summary and conclusions

Marcell Gáspár, Assistant lecturer A professor Dr. András Balogh, Associate

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áspár, M.; Balogh, A.: Effect of t8 5/5 cooling time

Budapest, 20th November 20




HSS

MSS

UHSS

Quenched and tempered HSS (Q+T)

km=10000

km=15000

l

Szakadás i nyúlás, Al, % Elongatiion, A, %

50 40 Mild

30

Welding difficulties d Cold cracks • Hydrogen diffusion • Tensile stress (limited deformation) • High carbon equivalent: 0.5 < CEVS960Q < 0.6 65

km=20000 CM

CEV  C 

n HS

20

LA HS


Mn Cr  Mo  V Cu  Ni   6 5 15 410

Q+T +T LA Q

MART

10

390

Keménnység, [HV]

LSS

60

0 0

200

400

600

800

1000

1200

1400

1600

Inhomogeneous HAZ

Tensile strength, R Rmm,,MPa MPa Szakítószilárdság,

Márkanév WELDOX 700 E WELDOX 900 E WELDOX 960 E WELDOX 1100 E WELDOX 1300 E

EN 10025-6

Rp0,2 [MPa]

Rm [MPa]

A5 [%]

CEV [%]

CET [%]

TKV [°C]

S690QL S900QL S960QL -

700 900 960 1100 1300

780-930 940 1100 940-1100 980-1150 1250-1550 1400-1700

14 12 12 10 8

0.43 0 55 0.55 0.55 0.59 0.65

0.29 0 36 0.36 0.37 0.35 0.42

-40


• Lower toughness • Hardened and softened zone

350 330 K G

310 290 270

0

3

6

9

12

15

18

Lenyomat

Selection of filler metal: Mismattch ratio 3




Budapest, 20th November 20 Institute of Materials Science and Technolog

HAZ pro operties

• Structure of HAZ in single and multip pass welds

Intercritically reheated coarse-graine ed zone (ICCGHAZ) Optical microscopic and microhardness s examination of HAZ in multipass welded ld d jjoint i t (S960QL)

• Critical areas:

Coarse grained: (CGHAZ) Intercritical (ICHAZ) Intercritically reheated coarse grained (ICCGHAZ) Subcritically reheated coarse grained (S SCCGHAZ)

5

4


HAZ pro operties


370

250


– – – –



Grouping of high h strength steels 70

2

-


135 (GMAW) PA position s = 15 mm 2% HNO3 (Nital) Load: HVM1


6




Physical simulation in welding w – GLEEBLE 3500 • Definition: physical simulation is the realiza ation of real technological processes in (nearly) real time and geometrical step • Application pp possibilities p in welding: g – HAZ test – Hot cracking » Nil strength temperature (NST) » Hot tensile test (HTT) – Cold cracking – Fusion and pressure welding processes • Parameters (function of specimen size): – Heating: 10 000 °C/s – Cooling: 10 000 °C/s – Velocity: 2000 mm/s – Maximal force: 100 kN (pressure/compre ession)


7



HAZ test – Sim mulation steps

• HAZ simulation: welding heat cycle models m – – – – – –

F(s,d) => thermocouple measurement or FEM v Hannerz Ev  2a  x  R  T  R, x   e Rykalin-2D 2 R  Rykalin-3D 2 2 2 a R  x  y  z cp  Rosenthal Exponential

• Inhomogeneous I h HAZ areas – The extension of HAZ areas is relatively small s due to the low heat input welding, that can be limitedlyy investigated g by y conventional material tests.

• Recommended specimen size: 10x10 0x70 mm • Possible material tests: – Optical/electron microscopic methods, ha ardness tests – Charpy-V test (10x10x55 mm), COD testss áspár, M.; Balogh, A.: Effect of t8 5/5 cooling time

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• HAZ areas (NST = 1403.8 ºC, prelim minary simulations): – CGHAZ: Tmax = 1350 ºC – ICHAZ: ICHAZ Tmax = 775 ºC – ICCGHAZ: Tmax = 1350, 775 ºC

– geometrical shape, surface quality

• Fitting of thermocouples to the surfac ce: – Thermocouple welder – NiCr-Ni (K type)

• t8.5/5 8 5/5 cooling times: – 5s – 15 s – 30 s

• Positioning of specimens in grips • Welding W ldi h heatt cycle: l Model: Rykalin-3D Thermo physical properties (JMatPro) Welding parameters Selection of maximal temperature

Thermocouples

GMAW

• Investigated steel category: C Si Mn P S Cr Ni WELDOX 960 0,17% 0,20% 1,23% 0,007% 0,002% 0,20% 0,06% Mo V Ti Cu Al Nb B N 0 599% 0 0,599% 0,041% 041% 0,003% 0 003% 0,01% 0 01% 0 0,053% 053% 0,015% 0 015% 0 0,001% 0,008% 0 008%

• Simulation • Evaluation áspár, M.; Balogh, A.: Effect of t8 5/5 cooling time

Physical simulation in welding – HAZ test

Selection of peak temperratures and cooling times

• Precise preparation of HAZ specimen ns

– – – –



Specimen Grips/jaws

9



WELDOX 960

RP0,2 MPa 1058

Rm MPa 1082

A5 % 14


KV (-40ºC C) J 70

1 10



HAZ heat cycles in single and a multipass welded joint

CEV 0,55 CET 0 36 0,36

Optical micro oscopic tests HAZ microstructure by optical micros scope: – Nital (2% HNO3) – t8.5/5 = 5 s

t8.5/5 = 5 s


t8.5/5 = 15 s

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t8.5/5 = 30 s


CGHAZ


ICHAZ Z

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ICCGHAZ






SEM tests

Hardnes ss tests

HAZ microstructure by scanning elec ctron microscope:

• Hardness tests:

– Nital (2% HNO3) – t8.5/5 = 15 s

– Evaluation: HVmax = 450 HV according to o EN 15614-1 for the 3rd group in CR ISO 15608 HAZ

CGHAZ

ICHA AZ

ICCGHAZ

Tmax, °C

Hardness, HV10 t8.5/5 = 5 s

t8.5/5 = 15 s

t8.5/5 = 30 0s

ICHAZ

775

323

323

311

CGHAZ

1350 1350 775 -

427

409

386

344

343

ICCGHAZ Base material

336

330 340 330…340

Hardness, HVM0.1

HAZ

Location

t8.5/5 = 5 s

t8.5/5 = 15 s

t8.5/5 = 30 s 8

360

440

355

ICHAZ

grain boundary grain center

301

283

267

grain boundary

479

449

494

grain center

355

327

313

ICCGHAZ Base material


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Summary, conclusions c

• Charpy-V test: – Evaluation: 27 J at -40 °C (according to EN 10025-6) – 3 specimens/heat i /h t cycle l => > calculation l l ti of of average Charpy Ch energy Base material

ICCGHAZ

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Toughness s properties


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• The most critical HAZ areas of WELDOX 960 9 E (S960QL, EN 10025-6) are the CGHAZ ICHAZ and ICCGHAZ in multipass welded joints. • CGHAZ, ICHAZ and ICCGHAZ were successfully performed by our GLEEBLE 3500 thermo mechanical physical simulator for t8,5/5 = 5 , 15 5 and 30 s cooling times. • The grain size of CGHAZ was 10 times highe er than the original Q+T microstructure (150-200 µm instead of 10 10-15 15 µm). µm) The measured maxximum hardness in case of low cooling time was close to the permitted maximum value of EN 15614-1 1 (450 HV). • In ICHAZ there was no significant difference between the hardness values and toughness of the three cooling times. times • The toughness of CGHAZ, ICHAZ and ICCGH HAZ was much lower than the fine-grained base material. The measured Charpy energy value es were close to the required minimum value, 27 J ICCGHAZ has the lowest toughness (5 s). J. s) • For the precise analysis of the toughness pro operties of HAZ the specimen number should be increased in case of CGHAZ due to the high scatter s noticed in impact energy values. • On the basis of simulation results the welding technology, including the optimal t8.5/5 cooling time range can be determined. • Further simulations are p planned for shorther cooling c g times ((2.5 s). ) áspár, M.; Balogh, A.: Effect of t8 5/5 cooling time

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Litera ature Gáspár, Gá á M M.; B Balogh, l h A A.: A h hegesztési té i paraméterek ét k hőh hőhatásövezetre tá ö t gyakorolt k lt h hatásának tá á k fi fizikai ik i szimulációval i lá ió l tö történő té ő vizsgálata i ál t S960QL acél él esetén, té Hegesztéstechnika, 2014/1 pp. 21-28. Bhadesia, H. K. D. H.; Honeycombe, R. W. K.: Steels Microstructure and Prope erties, Third Edition, Elsevier Linacre House, Jordan Hill, Oxford OX2 8DP, UK 2006. n Low Impurity 420, 550 and 700 MPa Yield Strength Thermomechanically Nevasmaa, P: Evaluation of HAZ Toughness Properties in Modern Low Carbon Processed Steels with Emphasis on Local Brittle Zones, Lisensiaatintyö, Univerrsity of Oulu, 1996. pp. 176. Laitinen, R.: Improvement of weld HAZ toughness at low heat input by controllin ng the distribution of M-A constituents, PhD Dissertation, University of Oulu, 2006. pp. 164. Węglowski, M.: Modern toughened steels – their properties and advantages, Biuletyn Instytutu Spawalnictwa, 2012/02. pp. 25-36. j , L. P.;; Laitinen,, R. O.;; Thinen,, S. A;; Suiikkanen,, P. P.: Hardness Profiles of Quenched Q Steel Heat Affected Zones,, Heikkilä,, S. J.;; Porter,, D.A.;; Karjalainen, Materials Science Forum Vol 762, Trans Tech Publications, Switzerland, 2013. pp. 722-727. Laitinen, R.; Porter, D. A.; Karjalainen, L. P.; Leiviskä, P.; Kömi, J.: Physical Sim mulation for Evaluating Heat-Affected Zone Toughness of High and Ultra-High Strength Steels, Materials Science Forum Vol. 762, Trans Tech Publications, Sw witzerland, 2013. pp. 711-716. Palotás, B.: Növelt folyáshatárú acélok keménysége különböző kritikus lehűlési idő esetén, IX. Országos Anyagtudományi Konferencia, Balatonkenese, Magyarország, 2013.10.13-2013.10.15. 2013.10.13 2013.10.15. Paper II/1. Komócsin, M.: Nagyszilárdságú acélok és hegeszthetőségük, Hegesztéstechnik ka, 2002/1, pp. 5–9. ] Sas, I.: Növelt folyáshatárú acélok hegesztésének gyakorlati tapasztalatai a Ruukki Zrt-ben, Cloos Szimpózium, BMF, 2009. ] Rittinger, J.: Termomechanikusan kezelt acélok hegesztése és a hegesztett köttések tulajdonsága, 25. Jubileumi Hegesztési Konferencia, 2010. pp. 119-143. ] Kuzsella, L.; Lukács, J.; Szűcs, K.: Fizikai szimulációval végzett vizsgálatok S96 60QL jelű, nagyszilárdságú acélon, GÉP, LXIII. évf. 4. sz., 2012. pp. 37-42. ] Érsek, É L.: Alvázak gyártása autódarukhoz nagyszilárdságú acélokból, Hegeszté éstechnika, 2008/1. pp. 37-41. ] Kovács, M.: Nagyszilárdságú finomszemcsés szerkezeti acélok hegesztése, He egesztéstechnika, 1992/3. pp. 14-16. ] Gáspár, M.; Balogh, A.: GMAW experiments for advanced (Q+T) high strength steels, Journal of Production Processes and Systems, Vol. 6 (1), University of Miskolc, Department of Materials Processing Technologies, 2013. pp. 9-24. ] Szunyogh, L.: Hegesztés és rokontechnológiák kézikönyv, Gépipari Tudományo os Egyesület, Budapest, 2007 ] LePera, F. S: Improved etching technique to emphasize martensite and bainite in high-strength, Dual-Phase steels, Journal of Metals March, 1980. pp. 38–39. ] Lukács, J., Kuzsella, L., Dobosy, Á., Pósalaky, D.: Hegesztési melegrepedés-érzékenység megítélése fizikai szimuláció segítségével, GÉP LXIV. évf. 8. sz. 2013. pp. 45-50. ] Koritárné Fótos, R.; Koncsik, Zs.; Lukács, J.: A fizikai szimuláció és alkalmazás sa az anyagtechnológiákban, „Műszaki Tudomány az É-K Moi. Régióban”, S l k 2012 Szolnok,


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Thank you for your y attention! [email protected] Acknowledgement The presented research work based d on the results achieved within the TÁMOP-4.2.1.B-10/2/KONV-2010-0001 1 project and carried out as part of the TÁMOP-4.2.2/A-11/1-KONV-2012-0029 Á 9 project in the framework of the New Széchenyi Plan. The realization of this s project is supported by the European Union and co Union, co-financed financed by the Europea an Social Fund. Fund áspár, M.; Balogh, A.: Effect of t8 5/5 cooling time

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ÓBUDAI EGYETEM BÁNKI DONÁT GÉPÉSZ ÉS BIZTONSÁGTECHNIKAI MÉRNÖKI KAR

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