Oil Drilling Winch Brake Wheel Of Medium Frequency Induction Hardening The Simulation And Experimental Research

The brake wheel is one key component of the petroleum drilling rig drawworks, which bears the responsibility of controlling the hook lifting, lowering, stopping and the running speed of the hook. The brake wheel is working under the condition with thermal load, mechanical impact load and friction load, while there still exists a big torque, so the most common forms of failure are work surface wear, heat fatigue cracks, fracture and so on. Therefore, the brake wheel is required to have good abrasion resistance on the surface, but have enough toughness in the heart, while the conventional quenching and tempering or common quenching can’t meet the surface and core requirements. So in this paper, we deal with the brake wheel by induction hardening heat treatment after quenching and tempering to improve the wear resistance and service life. By the simulation of temperature field, residual stress and experimental research, the microstructure, hardness distribution, residual stress, friction and wear properties were analyzed in details.As the induction hardening process is a complicated nonlinear electro-magnetic-thermal fields coupling process, so it is very complicated and difficult to measure the temperature field and residual stress distribution of the induction hardening specimen, and generally it could only measure the finite point data. In order to obtain the complete and detailed data of the related variables in the whole region, the induction hardening process was simulated and analyzed by using ANSYS/Multiphysics finite element analysis software in this paper. Using the indirect magnetic-thermal coupling method, we calculated the induction hardening heating temperature field distribution, the temperature field distribution after cooling by water spray, the temperature field distribution after cooling in the air for a long time, and the residual stress after quenching.We dealt the brake wheel with induction hardening by using some important results and process parameters of numerical simulation as reference and guide, and did the experiment research compared with the common quenching specimen, the results show that the simulation results were basically consistent with the experimental results in the surface temperature and residual stress; The tissue of hardening layer of induction hardening specimen is cryptocrystalline martensite, which is finer than the tissue of common quenching specimen, while there remains sorbite tissue in the heart; The hardened layer depth of induction hardening specimen is5mm, and the hardness emerges in gradient distribution from the surface to the core. In the hardened layer range, the hardness is higher than that of common quenching specimen(higher about30～50HV) from the surface to4mm far from the surface, while is slightly lower than that of common quenching specimen from4mm to5mm; The surface residual stress of induction hardening specimen and common quenching specimen shows as compressive stress, but the former(425.7MPa) is larger than the latter(318.4MPa); The friction coefficient between induction quenching specimen with couple parts (the average value is about0.4) is greater than that between common quenching or quenching and tempering specimen with couple parts (the average values are respectively about0.38and0.3), which has more excellent friction and braking properties. Under the same test conditions, the wear volume of induction hardening specimen is significantly smaller than that of common quenching, which show more excellent wear resistance.In order to further improve the wear resistance and fatigue cracks resistance ability of the brake wheel, the specimen after induction hardening was strengthened by using shot peening method, and we mainly researched the change of hardness, residual stress and wear properties before and after shot peening. The test results show that the microhardness of the strengthened layer was improved largely, and the maximum value was719.5HV, compared with the specimen before shot peening, it was improved8.6%. Along with the increase of the distance from the surface, the hardness was tended to converge before and after shot peening, and the depth range of strengthened layer is0.5mm～1mm; In the shot peening process, the specimen surface emerges severe plastic deformation, so the residual compressive stress of strengthened layer was increased, and the value of surface compressive residual stress is625.3MPa, which improves199.6MPa than that before shot peening; The wear resistance was increased and the wear weightlessness was reduced after shot peening. The wear weightlessness of the specimen before shot peening was39.5mg after wearing80min, but37mg after shot peening, which was reduced by6.8%.