Abstract:
Provided are a high-strength, high-manganese steel wire rod having excellent cold heading quality and not requiring spheroidizing and quenching-tempering treatments during manufacturing a bolt and a method of manufacturing a bolt using the steel wire rod. The method of manufacturing a steel wire rod includes heating a steel containing 12 to 25 wt % of Mn within a temperature range of 1100° C. to 1250° C., hot rolling the heated steel within a temperature range of 700° C. to 1100° C., and cooling the hot rolled steel to a temperature of 200° C. or less and cold caliber rolling or drawing to manufacture a steel wire rod.
Abstract:
The present invention provides an emergency control apparatus, and method which maintains the power flow between a battery and an inverter and the operation state of an electric vehicle in the event of failure of a bidirectional DC-DC converter connected between the battery as a power source and the inverter for operating a drive motor.
Abstract:
The present invention provides a method for compensating nonlinearity of a resolver to control a motor in hybrid and fuel cell vehicles, thereby stably controlling the motor current during high-torque and high-speed operation. In preferred aspects, the present invention provides a method for compensating nonlinearity of a resolver to control a motor in hybrid and fuel cell vehicles, the method including collecting resolver position data; determining whether to perform resolver position correction in the corresponding vehicle; and compensating nonlinearity of the resolver based on the collected resolver position data, if it is determined that the resolver position correction is not performed.
Abstract:
A high-ductility, high-strength and high Mn steel strip used for steel strips of automobiles requiring superior formability and high strength, a plated steel strip produced by using the same, and a manufacturing method thereof are disclosed. The high Mn steel strip comprises, by weight %, 0.2˜1.5% of C, 10˜25% of Mn, 0.01˜3.0% of Al, 0.005˜2.0% of Si, 0.03% or less of P, 0.03% or less of S, 0.040% or less of N, and the balance of Fe and other unavoidable impurities. The high-ductility, high-strength and high Mn steel strip, and the plated steel strip produced by using the same have superior surface properties and plating characteristics.
Abstract:
Provided is a high manganese nitrogen-containing steel sheet. The high manganese nitrogen-containing steel sheet according to the present invention comprises 0.5 to 1.0 wt % of carbon, 10 to 20 wt % of manganese, 0.02 to 0.3 wt % of nitrogen, with a remainder of Fe and unavoidable impurities. The high manganese nitrogen-containing steel sheet according to the present invention produces an austenite phase at room temperature, in which the stacking fault energy is effectively controlled by adding chrome and nitrogen. Accordingly, the high manganese nitrogen-containing steel sheet of the present invention produces a mechanical twin during the plastic deformation of the steel sheet, thereby increasing the work hardening rate, tensile strength, and workability.
Abstract:
The present invention provides a method for compensating nonlinearity of a resolver to control a motor in hybrid and fuel cell vehicles, thereby stably controlling the motor current during high-torque and high-speed operation. In preferred aspects, the present invention provides a method for compensating nonlinearity of a resolver to control a motor in hybrid and fuel cell vehicles, the method including collecting resolver position data; determining whether to perform resolver position correction in the corresponding vehicle; and compensating nonlinearity of the resolver based on the collected resolver position data, if it is determined that the resolver position correction is not performed.
Abstract:
The present invention provides a battery charging apparatus with reduced weight, volume and manufacturing cost. The apparatus includes: an alternating current power source including a first electrode and a second electrode and supplying an alternating voltage for charging the battery; a diode including an anode electrode connected to the battery and a cathode electrode connected to the second electrode and half-wave rectifying the alternating voltage applied from the alternating current power source; a three-phase motor connected to the first electrode and transmitting to the battery the half-wave rectified voltage applied from the diode and the alternating current power source; and an inverter connected between the three-phase motor and the battery and converting the voltage applied from the three-phase motor into a direct voltage to transmit the direct voltage to the battery. Alternatively, the apparatus may comprise an alternating current power source, an inverter, a three-phase motor and a switching unit.