A vanadium silicon nitride film formed as a hard film to a base material satisfies 0.30≤a/b≤1.7 and 0.24≤b≤0.36 when a=vanadium element concentration [at %]/(vanadium element concentration [at %]+silicon element concentration [at %]+nitrogen element concentration [at %]) and b=silicon element concentration [at %]/(vanadium element concentration [at %]+silicon element concentration [at %]+nitrogen element concentration [at %]), and has a hardness of 2300 HV or more.

A method for manufacturing a forged article, capable of improving the durability of a die for forging is provided. The method, includes forging a steel material by using a die, by spraying or applying a water-soluble polymer lubricant containing 0.01 to 0.98 mass % of a water-soluble sulfate onto a working surface of the die, the die being made of a raw material having a constituent composition of by mass %, of 0.4 to 0.7% of C, 1.0% or less of Si, 1.0% or less of Mn, 4.0 to 6.0% of Cr, 2.0 to 4.0% of (Mo+½W), 0.5 to 2.5% of (V+Nb), 0 to 1.0% of Ni, 0 to 5.0% of Co, 0.02% or less of N, and a remnant composed of Fe and impurities, and having hardness of 55 to 60 HRC, and the die including a nitrided layer or a nitrosulfidized layer on the working surface thereof.

A method for manufacturing a forged article, capable of improving the durability of a die for forging is provided. The method, includes forging a steel material by using a die, by spraying or applying a water-soluble polymer lubricant containing 0.01 to 0.98 mass % of a water-soluble sulfate onto a working surface of the die, the die being made of a raw material having a constituent composition of by mass %, of 0.4 to 0.7% of C, 1.0% or less of Si, 1.0% or less of Mn, 4.0 to 6.0% of Cr, 2.0 to 4.0% of (Mo+½W), 0.5 to 2.5% of (V+Nb), 0 to 1.0% of Ni, 0 to 5.0% of Co, 0.02% or less of N, and a remnant composed of Fe and impurities, and having hardness of 55 to 60 HRC, and the die including a nitrided layer or a nitrosulfidized layer on the working surface thereof.

The hot work tool steel or hot work tool contains, in mass %, 0.25 to 0.45% of C, 0.1 to 0.4% of Si, 0.5 to 0.9% of Mn, 0 to 0.6% of Ni, 4.9 to 5.5% of Cr, 1.3 to 2.3% of Mo or 1/2W by itself or 1.3 to 2.3% of (Mo+1/2W) in combination, 0.6 to 0.9% of V, and a balance of Fe and impurities, and value A and value B calculated by the following Formula 1 and Formula 2 satisfy that value A is 6.00 or more and value B is 1.00 or less.

Value A=−0.7(% Si)+1.5(% Mn)+1.3(% Ni)+0.9(% Cr)+0.6(%(Mo+1/2W))+0.3(% V)   Formula 1

Value B=1.9(% C)+0.043(% Si)+0.12(% Mn)+0.09(% Ni)+0.042(% Cr)+0.03(%(Mo+1/2W))−0.12(% V)   Formula 2

The invention relates to a method and an apparatus for producing a rod- or pipe-shaped intermediate product provided with an end face (106) from a semi-finished connecting element (102) made of metal, in particular an insertion end of a drill or chisel attached in an axially movable manner in the chuck of a hammer drill, the connecting element (100′) having at least one rotary entrainment surface (162, 164) and at least one locking depression (122, 124), the locking depression (122, 124) being preferably embodied as a locking groove, a semi-finished connecting element (102) being provided, the at least one rotary entrainment surface (162, 164) being formed in the semi-finished connecting element (102) by axially forcing the semi-finished connecting element (102) in the direction of the longitudinal axis (136) of the semi-finished connecting element (102) into a longitudinal die opening (204) of a die (202), or being embossed in the semi-finished connecting element (102) by radially applying at least one movable forming body (206), and the at least one locking depression (122, 124) being embossed by radially applying at least one or multiple forming bodies (206) that are movable in the same die (202).

A drawing unit with a segment reciprocating die for drawing metal segments comprises a tensioning device arranged to advance a shaped specimen through an array of dies that create a shaped orifice with the spacing formed between the dies. These dies segments act under the influence of a powered unit to move in a reciprocating motion that causes the spacings between segments to increase and decrease synchronously thereby shaping the metal segments.

A drawing unit with a segment reciprocating die for drawing metal segments comprises a tensioning device arranged to advance a shaped specimen through an array of dies that create a shaped orifice with the spacing formed between the dies. These dies segments act under the influence of a powered unit to move in a reciprocating motion that causes the spacings between segments to increase and decrease synchronously thereby shaping the metal segments.

A gas generator includes an elongated cylindrical housing main body and a plug which closes an axial end portion of the housing main body. The plug made of a metal includes a substantially columnar body portion, a first flange portion located on a side of a first end surface, and a second flange portion located on a side of a second end surface. An annular groove portion defined by the body portion, the first flange portion, and the second flange portion is located in a circumferential surface of the plug. A metal flow in a portion which appears in a surface layer of the circumferential surface of the plug including a surface of the annular groove portion continuously extends to reach the second end surface from the first end surface along the circumferential surface without discontinuity in the circumferential surface.

The present invention provides a method and a device for manufacturing a safety vent of a cap plate for a secondary battery, a method for manufacturing a cap plate using the method for manufacturing a safety vent, and a cap plate for a secondary battery manufactured by the method for manufacturing a cap plate, which can prevent a molding defect in a safety vent of the strength of a vent plate becoming excessively great, by easily molding the safety vent with only one or two times of forging processing in order to prevent a phenomenon in which hardening by forging occurs, during forging, in the vent plate formed at the lower part of the safety vent.

A die holder mounts a die to form heads on nails or screws. A top surface of the die includes a groove for longitudinally receiving and holding an elongate body. The die has a recess merging into the groove at one end of the groove to form a nail or screw head. The die is conical for press fit by contact with an inner surface of a bore or hole in the die holder. A top surface of the die is planar to a top surface of the die holder with a bottom surface engaging bottom part of the die holder. The bottom portion of the die has a recess or engaging with a corresponding protrusion die holder fixing an angular orientation of the groove relative to the die holder. Two opposite dies are brought together by two opposite die holders forming the head.