| High carbon steel wire strength has good elasticity and wear resistance, is the main raw material of steel wire, steel cord, spring and so on. Studying on the thermal deformation behavior and construct the deformation resistance model and hot processing map, we can provide basis for the improvement of high carbon steel wire rod production process optimization and material toughness.This study according to 65 high carbon steel as the research object, using Gleeble-3800 thermal simulation experiment machine, the casting state, pre-finishing state as well as the finished product of hot compression experiments. Based on the experimental data, the constitutive model and the heat treatment process of 65 steel with three kinds of state are constructed. The finite element simulation was carried out using the ABAQUS software to the optimal deformation parameters. Finally, the relationship between the structure change, the content of the cable, the spacing of the pearlite, the hardness and the cooling rate in the cooling process after rolling is analyzed. The main conclusions are as follows:(1) Based on the hot deformation behavior of 65 high carbon steel, deformation temperature and strain rate as the main factors affecting the deformation resistance should be less impact on the variables. And establish the model of deformation resistance of three kinds of state, from model of resistance to deformation can be seen casting blank, pre-finishing, product reference slip resistance gradually increases,respectively 147.05 MPa and 150 MPa, 165.0 7MPa. In deformation temperature900 ℃, the deformation is 0.4, variable rate 1s-1. According to the model of deformation resistance of the establishment of calculation that casting blank,pre-finishing mill and finished the deformation resistance value followed by 124.8 MPa,143.2 MPa and 157.9 MPa. Therefore, in the same deformation conditions, the material of the initial state of deformation resistance is larger, casting blank, pre-finishing mill and finished the deformation resistance is increased gradually.(2) Based on the hot processing map of casting, pre-finishing and finished products,determine the reasonable processing zone under different conditions and the flow instability region cast the reasonable processing area and flow instability region for1040 ~ 1050 ℃ /0.01~0.08 s-1and 920~950 ℃ /0.006~0.01 s-1, pre-finishing mill reasonable processing zones and rheological lost stability for 800~880 ℃/0.006~0.01s-1 and 880 ~ 1000 ℃ /0.006 ~ 0.6 s-1, and finished the reasonable processing and rheological lost stability for 800~880 ℃/0.04~0.06 s-1 and 950~1000 ℃/0.05~0.1 s-1.Reasonable processing temperature of billet, pre-finishing and finished lower than cast.According to the established hot processing map, microstructure and morphology of the comparative reasonable processing zone and flow instability region that reasonable processing zone of deformation parameters with homogeneous microstructure, and flow instability region deformation parameters of grain size of microstructure.(3) The product of deformation resistance model and the ABAQUS finite element software combined, under the optimal deformation parameters(880 ℃ /10 s-1) of finished compression process simulation, got the parameters under the stress distribution under the conditions better than other stress distribution, and verify the model of deformation resistance of finished products.(4) By metallographic and SEM analysis, get cable content and pearlite layer spacing, the cooling rate is less than 10 ℃/s, cable content increases with the increase of cooling rate; cooling rate more than 10 ℃ /s, cable content decreased with the increase of cooling rate. When the cooling rate is 10 ℃/s, the content of the cable is the highest, which is 93.97%. |
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