Mould for cold forging and manufacture method thereof

A mold and cold forging technology, which is applied in the field of cold forging molds and its manufacturing, can solve the problems of wear suppression effect and insufficient, and achieve the effect of good holding force, reduced friction, and not easy to wear

CN101380659AActive Publication Date: 2009-03-11DAIDO STEEL CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2009-03-11

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Abstract

The invention aims to provide a mould for cold forging and a manufacturing method thereof, and inhibits sticking a finished produced forged by the mould for the cold forging through preventing abrasion or peeling of a hard membrane formed on the surface of the mould for the cold forging. The mould for the cold forging comprises a single-layer or multi-layer membrane arranged on a design surface of the mould, and the membrane is formed by one, two or more than two substances selected from the following cluster, wherein the cluster comprises carbide, nitride or carbonitride containing one, two or more than two metals in 4A family, 5A family and 6A family, and nitride containing one, two or more than two metals in the 4A family, the 5A family and the 6A family and one or two elements of Si and Al, wherein the 4A family means Ti, Zr and Hf; the 5A family means V, Nb and Ta; the 6A family means Cr, Mo and W; the surface roughness Ra of the membrane measured from any direction is more than or equal to 0.05 micron or less than or equal to 0.50 micron.
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Description

technical field

[0001] The present invention relates to a die for cold forging and a method of manufacturing the same, and more specifically relates to a technique for suppressing the formation of a molded product forged by a die for cold forging ( High Tensile Steel Plate) sticky type. Background technique

[0002] To reduce vehicle CO 2 To reduce emissions and ensure crash safety, it is necessary to make the vehicle body lighter and more rigid, and the utilization rate of high-tensile steel plates is rapidly increasing. However, due to the high strength of the high-tensile steel sheet, when the high-tensile steel sheet is stamped with a die for cold forging, the steel material and the die for cold forging will have intense friction, resulting in insufficient oil film, and the steel material and the die for cold forging will be easily separated. Minute heat sticking occurs in the mold, resulting in a defect called sticking (string-like cracks in the molded product, that i...

Examples

Embodiment

[0070] Hereinafter, examples and comparative examples of the present invention will be described.

[0071] (Manufacturing of punches and dies)

[0072] For Examples 1 to 18 and Comparative Examples 1 to 5, the JISSKD11 of 59HRC is processed and prepared figure 2 The punch and die shown.

[0073] Subsequently, to the base surface of the stamping die of embodiment 1,4,6,9~11,13,16,17,18 and comparative example 2~4 ( figure 2 The part indicated by the dotted line in the middle), respectively, the plasma nitriding treatment with the overall thickness of the hardened layer being 0.05mm.

[0074] Then, to the die surface of embodiment 1~18 and comparative example 2~5 ( figure 2 The part indicated by the dotted line in ) is projected by shot peening to form fine unevenness. At this time, for Examples 1 to 18 and Comparative Examples 3 to 5, shot peening was performed at a projection speed of 100 m / sec using steel shot peening media having a particle size of 100 μm or less. At...