The structure and properties of laser seam stepper system (LSS) welded the low alloy high strength steel DOCOL 1200M with martensitic structure
DOI:
https://doi.org/10.18063/msacm.v2i1.660Keywords:
DOCOL 1200M steel, Laser SEAM Stepper, welding, martensiteAbstract
This paper will present the influence of joining process parameters on the structure and properties of overlapped welded joints of 1.8 mm DOCOL 1200M steel. The obtained welded joints were subjected to micro- and macroscopic metallographic examination and hardness measurement. The visual inspections and non-destructive testing made it possible to develop the field of welding parameters to allow obtaining full penetration joints (depending on requirements) or partial penetration joints. For present welding parameters, i.e. feed rate and weld length, which are constant, the actual length of weld is determined by welding frequency. In each case, the microscopic examinations revealed martensitic structure in the weld area, and with the increase in linear welding energy the size of martensite needles became larger, especially in relation to the base material. In HAZ, the martensitic structure is tempered. It has been shown that with appropriately selected parameters the Laser SEAM Stepper method is suitable for welding the DOCOL 1200M steel. With the increase in welding power, the penetration depth increases.References
Grajcar A, Różański M. Weldability of high-strength multiphase AHSS steels. Przegląd Spawalnictwa No. 3/2014, p. 22–27.
Nishioka K, Ichikawa K. Progress in termomechanical control of steel plates and their commercialization. Science and Technology of Advanced Materials 2012; 13(2): 1–20.
Krajewski S, Nowacki J. Microstructure and mechanical properties of Advanced High-Strength Steels (AHSS). Przegląd Spawalnictwa No. 7/2011, p. 45–50.
Stano S. Laser welding of steel sheets differentiated in thickness for designed tailored blanks. Biuletyn Instytutu Spawalnictwa No. 2/2005, p. 24–28.
Chen B, Yu H. Hot ductility behaviour of V-N and V-Nb microalloyed steels. International Journal of Minerals, Metallurgy and Materials 2012; 19(6): 525.
Lee HS, K Park. Evaluation of high strength TMCP steel weld for use in cold regions. Journal of Constructional Steel Research 2012; 74: 134–139.
Górka J. Weldability of thermomechanically treated steels having a high yield point. Archives of Metallurgy and Materials 2015; 60(1): 469–475.
Lisiecki A. Diode laser welding of high yield steel. Proc. of SPIE Vol. 8703, Laser Technology 2012: Applications of Lasers, 87030S (January 22, 2013).
Adamczyk J, Opiela M. Influence of the thermo-mechanical treatment parameters on the inhomogeneity of the austenite structure and mechanical properties of the Cr-Mo steel with Nb, Ti and B microadditions. Journal of Materials Processing Technology 2004; 157–158: 456–461.
Górka J. Study of structural changes in S700MC steel thermomechanically treated under the influence of simulated welding thermal cycles Indian Journal of Engineering and Materials Sciences 2015; 22: 497–502.
Lisiecki A, Kurc-Lisiecka A. Laser welding of the new grade of advanced high-strength steel Domex 960. Erosion wear resistance of Titanium-Matrix Composite Ti/TiN produced by diode-Laser Gas Nitriding. Materiali in Tehnologije / Materials and Technology 2017; 51(1): 29–34.
Lisiecki A, Kurc-Lisiecka A. Laser welding of the new grade of advanced high-strength steel Domex 960. Materiali in Tehnologije / Materials and Technology 2017; 51(2): 199–204.
Janicki D. Laser cladding of Inconel 625-based composite coatings reinforced by porous chromium carbide particles. Optics & Laser Technology 2017; 94: 6–14.
Janicki D, Musztyfaga-Staszuk M. Direct Diode Laser Cladding of Inconel 625/WC Composite Coatings. Strojniški vestnik - Journal of Mechanical Engineering 2016; 62(6): 363–372.
Grajcar A. Thermodynamic analysis of precipitation processes in Nb-Ti-microalloyed Si-Al TRIP steel. Journal of Thermal Analysis and Calorimetry 2014; 118(2): 1011–1020.
Morawiec M, Różański M, Grajcar A, et al. Effect of dual beam laser welding on microstructure-property relationships of hot-rolled complex phase steel sheets. Archives of Civil and Mechanical Engineering 2017; 17: 145–153.
Opiela M. Thermodynamic analysis of the precipitation of carbonitrides in microalloyed steels. Materiali in Tehnologije 2015; 49(3): 395–401.
Opiela M. Elaboration of thermomechanical treatment conditions of Ti-V and Ti-Nb-V microalloyed forging steels. Archives of Metallurgy and Materials 2014; 59(3): 1181–1188.
Grajcar A, Różański M, Stano S. Effect of heat input on microstructure and hardness distribution of laser welded Si-Al TRIP-type steel. Advances Material Science Engineering 2014; Article ID 658947, pp. 1–8.
Godwin K, Yong O. Microstructure and fatigue performance of butt-welded joints in advanced high-strength steels. Materials Science & Engineering A 2014; 597: 342–348.
Wang W, Li M, He C, et al. Experimental study on high strain rate behavior of high strength 600–1000MPa dual phase steels and 1200MPa fully martensitic steels. Materials and Design 2013; 47: 510–521.
