Abstract: A spring wire is subjected to a first shot peening process and a second shot peening process. In the first shot peening process, a first shot is projected on the spring wire at a first projectile speed. High kinetic energy of the first shot produces compressive residual stress in a region ranging from the surface of the spring wire to a deep position. In the second spring wire process, a second shot is projected at a second projectile speed lower than the speed of the first shot. The kinetic energy of the second shot is lower than that of the first shot. The low kinetic energy of the second shot increases the compressive residual stress in a region near the surface of the spring wire.

Abstract: A spring wire is subjected to a first shot peening process and a second shot peening process. In the first shot peening process, a first, shot is projected on the spring wire at a first projectile speed. High kinetic energy of the first shot produces compressive residual stress in a region ranging from the surface of the spring wire to a deep position. In the second spring wire process, a second shot is projected at a second projectile speed lower than the speed of the first shot. The kinetic energy of the second shot is lower than that of the first shot. The low kinetic energy of the second shot increases the compressive residual stress in a region near the surface of the spring wire.

Abstract: An apparatus for galvanizing which comprises a plating tank, a dross removing tank, a means to transfer the molten metal bath from the plating tank to the dross removing tank, and an opening located on the plating tank to recycle the molten metal bath from the dross removing tank to the plating tank.

Abstract: The method for hot dip galvanizing comprises the steps of: dividing a plating vessel holding a molten metal into a plating tank and a dross removing tank; conducting hot dip galvanizing to a steel strip by immersing thereof in the molten metal bath; then transferring the molten metal bath from the plating tank to the dross removing tank; removing a dross from the molten metal bath in the dross removing tank; and recycling the molten metal bath from the dross removing tank to the plating tank through an opening located on the plating tank. The apparatus for galvanizing comprises a plating tank, a dross removing tank, a means to transfer the molten metal bath from the plating tank to the dross removing tank, and an opening located on the plating tank to recycle the molten metal bath from the dross removing tank to the plating tank.

Abstract: The method for hot dip galvanizing comprises the steps of: dividing a plating vessel holding a molten metal into a plating tank and a dross removing tank; conducting hot dip galvanizing to a steel strip by immersing thereof in the molten metal bath; then transferring the molten metal bath from the plating tank to the dross removing tank; removing a dross from the molten metal bath in the dross removing tank; and recycling the molten metal bath from the dross removing tank to the plating tank through an opening located on the plating tank. The apparatus for galvanizing comprises a plating tank, a dross removing tank, a means to transfer the molten metal bath from the plating tank to the dross removing tank, and an opening located on the plating tank to recycle the molten metal bath from the dross removing tank to the plating tank.