[Object]

A pressing die and a press working method that can achieve both facilitation of management of an appropriate clearance and working durability at a high level are provided.

[Solving Means]

The pressing die of the present invention is a pressing die for press working a metal material using a punch part and a die part. A working surface of one of the punch part and the die part is coated with a diamond film the working surface contacting with the metal material. A working surface of the other one of the punch part and the die part is coated with a surface treatment film having a Vickers hardness of 8000 Hv or less the working surface contacting with the metal material.

[Object]

A pressing die and a press working method that can achieve both facilitation of management of an appropriate clearance and working durability at a high level are provided.

[Solving Means]

The pressing die of the present invention is a pressing die for press working a metal material using a punch part and a die part. A working surface of one of the punch part and the die part is coated with a diamond film the working surface contacting with the metal material. A working surface of the other one of the punch part and the die part is coated with a surface treatment film having a Vickers hardness of 8000 Hv or less the working surface contacting with the metal material.

A cold working apparatus (102; 202) for forming a blank (104), the cold working apparatus (102; 202) comprising a first die (106; 206) and a second die (108), wherein the first die (106; 206) has at least one die cavity (110; 210), and the second die (108) has at least one die protrusion (112), wherein the cold working apparatus (102; 202) is configured to, by means of the first and second dies (106, 108; 206, 108), press form the blank (104) placed between the first and second dies (106, 108; 206, 108). At least one of the first and second dies (106, 108; 206, 108) has a draw radius (116; 216), wherein a member (118; 218) is attached to a die (106; 206) which has a draw radius (116; 216). At least a portion (119; 219) of the member (118; 218) is positioned adjacent to or on the draw radius (116; 216). The member (118; 218) defines a first press forming surface (120; 220), and the die (106; 206) holding the member (118; 218) defines a second press forming surface (122; 222) outside the first press forming surface (120; 220). The member (118; 218) and the die (106; 206), which holds the member (118; 218), are configured such that during the same press forming, a first friction arises between the blank (104) and the first press forming surface (120; 220) when the blank (104) is in contact with the member (118; 218) and a second friction arises between the blank (104) and the second press forming surface (122; 222) when the blank (104) is in contact with the die (106; 206) which holds the member (118; 218), the first friction being lower than the second friction. A method for cold working a blank (104)

A cold working apparatus (102; 202) for forming a blank (104), the cold working apparatus (102; 202) comprising a first die (106; 206) and a second die (108), wherein the first die (106; 206) has at least one die cavity (110; 210), and the second die (108) has at least one die protrusion (112), wherein the cold working apparatus (102; 202) is configured to, by means of the first and second dies (106, 108; 206, 108), press form the blank (104) placed between the first and second dies (106, 108; 206, 108). At least one of the first and second dies (106, 108; 206, 108) has a draw radius (116; 216), wherein a member (118; 218) is attached to a die (106; 206) which has a draw radius (116; 216). At least a portion (119; 219) of the member (118; 218) is positioned adjacent to or on the draw radius (116; 216). The member (118; 218) defines a first press forming surface (120; 220), and the die (106; 206) holding the member (118; 218) defines a second press forming surface (122; 222) outside the first press forming surface (120; 220). The member (118; 218) and the die (106; 206), which holds the member (118; 218), are configured such that during the same press forming, a first friction arises between the blank (104) and the first press forming surface (120; 220) when the blank (104) is in contact with the member (118; 218) and a second friction arises between the blank (104) and the second press forming surface (122; 222) when the blank (104) is in contact with the die (106; 206) which holds the member (118; 218), the first friction being lower than the second friction. A method for cold working a blank (104)

A rotary press die has a rotating die forming a negative angle part on a plate-like work and a fixed die arranged outside the rotating die and forming a molding part except for the negative angle part on the work. The rotating die is a press molding die which is formed such that the press molding die rotates about a rotating axis when the work is removed and can be retracted inside the fixed die. A rotating block is configured by a fixed piece arranged on the fixing table and having a concave slide surface having the rotating axis as a center. A moving piece is arranged on the rotating die and having a convex slide surface which can slide on the concave slide surface by using the rotating axis as a center. An opening angle between the concave slide surface and the convex slide surface is 80° to 100°.

A rotary press die has a rotating die forming a negative angle part on a plate-like work and a fixed die arranged outside the rotating die and forming a molding part except for the negative angle part on the work. The rotating die is a press molding die which is formed such that the press molding die rotates about a rotating axis when the work is removed and can be retracted inside the fixed die. A rotating block is configured by a fixed piece arranged on the fixing table and having a concave slide surface having the rotating axis as a center. A moving piece is arranged on the rotating die and having a convex slide surface which can slide on the concave slide surface by using the rotating axis as a center. An opening angle between the concave slide surface and the convex slide surface is 80° to 100°.

A coated mold which can exhibit good sliding properties, and has further reduced droplets and excellent durability. The coated mold has a hard coating on a work surface, the hard coating including layer A in which layer a1 and layer a2 are alternately laminated, wherein the layer a1 is composed of a Cr-based nitride and has a thickness of 100 nm or less, and the layer a2 is composed of a nitride or carbonitride of (V.sub.1-aM.sub.a) (M is at least one selected from Mo and W), has an atomic ratio a of M to the sum of V and M of 0.05 or more and 0.45 or less, and has a thickness of 80 nm or less. Also: a method for manufacturing a coated mold; and a hard coat-forming target which can be used in the method for manufacturing a coated mold.

An example system includes a first stamping portion having a first surface to form a corresponding stamped surface on a metal component to be stamped, and a second stamping portion having a second surface, the second surface to oppose the first surface of the first stamping portion during stamping of the metal component. The second surface includes a metal flow receiving feature, the metal flow receiving feature including a non-flat surface to attenuate an amount of metal flowing therein during stamping of the metal component between the first stamping portion and the second stamping portion.

The present application provides a hot-work die steel and a preparation method thereof wherein the chemical constituents of the hot-work die steel in mass percentage are as follows: C: 0.20-0.32 wt %, Si: ≤0.5 wt %, Mn: ≤0.5 wt %, Cr: 1.5-2.8 wt %, Mo: 1.5-2.5 wt %, W: 0.5-1.2 wt %, Ni: 0.5-1.6 wt %, V: 0.15-0.7 wt %, Nb: 0.01-0.1 wt %, and a balance of iron, wherein an alloying degree is 5-7%; a tensile strength of the hot-work die steel at 700° C. is 560-700 MPa; a value of hardness of the hot-work die steel at room temperature is 32-38 HRC after holding at 700° C. for 3-5 h; and the hot-work die steel has an elongation of 14% to 16% at room temperature, a percentage reduction of area of 48% to 65%, and an impact toughness of 52-63 J at room temperature. The hot-work die steel of the present application has an excellent thermal stability as well as a good plasticity and a toughness at room temperature.

A rotary press die has a rotating die forming a negative angle part on a plate-like work and a fixed die arranged outside the rotating die and forming a molding part except for the negative angle part on the work. The rotating die is a press molding die which is formed such that the press molding die rotates about a rotating axis when the work is removed and can be retracted inside the fixed die. A rotating block is configured by a fixed piece arranged on the fixing table and having a concave slide surface having the rotating axis as a center. A moving piece is arranged on the rotating die and having a convex slide surface which can slide on the concave slide surface by using the rotating axis as a center. An opening angle between the concave slide surface and the convex slide surface is 80° to 100°.