RU2342445C1 - Strengthening technique of shearing die - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention concerns field of tool thermal treatment and can be used at manufacturing of shearing dies for notching. For endurance increasing of puncheon and matrix, hardened surface of puncheon and matrix are subjected to mechanical operation with margin implementation on its surface, then it is implemented fixing and positioning of matrix and puncheon blanks and implemented surface laser hardening with margin melting by all its high by means of ray movement by edge perimeter, oriented perpendicularly to anterior surface, at that smoothing is implemented by side surface.

EFFECT: endurance increasing of puncheon and matrix.

1 ex, 2 dwg

Description

The invention relates to mechanical engineering, in particular to the field of heat treatment of a tool.

There is a method of hardening the separation dies with a laser beam directed perpendicular to the hardened surface and moving parallel to it (Kovalenko BC, Verkhoturov AD, Golovko LF, Podchernyaeva II Laser and electroerosive hardening of materials. M: Nauka, 1986 , p. 241, Fig. 4.7).

However, the known method has significant disadvantages. When hardening along the front surface, the hardened layer has a shallow depth and is removed during regrinding as it is used. During the period of operation of the stamp requires repeated re-hardening, which increases the cost and cost of hardening.

When laser hardening along the lateral surface (in those cases when it is technologically feasible) additional equipment is required, the hardening time is significantly increased and a constant surface hardening hardness is not achieved due to the formation of laser exposure zones.

The prototype of the claimed invention is a method of hardening a stamp, including the manufacture of working parts with allowances for machining the front surface after hardening, laser hardening with fusion of the working edge with a beam directed perpendicular to the front surface and moving in the direction from the center of the punch to the periphery of the matrix to the cutting edges perpendicular to them contour. In this case, a heat-strengthened zone is formed on the die and punch along the working contour with increasing depth to the edge of the cutting edge. After hardening, final fine-tuning of the front surfaces of the stamp is carried out in order to remove edge fusion (RU No. 2033435 C1, 6 C21D 1/09, C21D 9/22, 1995).

However, the depth of hardening remains insufficient to be limited to one hardening, and subsequent hardening treatments are required. This increases the cost and cost of the stamp and reduces its durability due to additional machining of the fused front surface after each subsequent laser hardening. Great are the time and other costs of hardening.

The present invention was based on the task of laser hardening of the side surface to a height equal to the total value of all regrindings when the stamp is operating at minimum cost and cost regardless of the configuration and size of the side surface with high processability and quality of the hardened layer.

This is achieved by fusing the allowance with a laser beam perpendicular to the front surface and moving parallel to the edge. The allowance is performed during the machining of the punch and die blanks with Z dimensions sufficient to allow high-quality melting and subsequent finishing processing of the melted surface by grinding, and in height h equal to (greater) than the total removal during refining.

Figure 1 shows a section of the matrix, figure 2 is a section of a punch with allowances for reflow and final machining of the fused surface, as well as the location of the laser beam relative to the front surface.

The method of hardening includes the following operations: machining the matrix (punch) with allowances for reflow during laser processing and final machining, laser hardening by reflowing the allowance and final machining of the side surface.

The method is implemented as follows. The matrix (punch) is mounted on the table of the laser unit and positioned. The operating mode is turned on and the allowance is melted to the entire height of the side surface when the beam moves parallel to the edge of the matrix (punch). At the end of the reflow, the matrix (punch) is subjected to finishing machining of the molten side surface.

The method can be used at engineering enterprises in tool production in the manufacture of dies.

Example

Punches and dies were made for punching holes in cold-rolled low-carbon steel with a diameter of d = 30 mm on a VIPROS Queen 368 coordinate-turret press. The blanks were made of high-alloy heat-resistant tool steel P6M5 GOST 19265-73. The delivery status is a circle with a diameter of 60 mm (punch) and a diameter of 90 mm (matrix). The machining of the blanks was carried out in accordance with the drawings and the technology adopted by the factories for the manufacture of dies for punching holes. Additionally, an allowance of Z = 0.2 mm was established along the lateral surface of the punch to a height of h = 5 mm and the lateral surface of the die to a height of h = 3 mm. The allowance Z = 0.2 mm was assigned taking into account the high-quality fusion of the side surfaces of the punch and die and the subsequent finishing machining by grinding.

Volumetric heat treatment was performed according to standard conditions for P6M5. Hardness of hardened and tempered HRC 63 steel.

Laser hardening with fusion of the allowance along the lateral surfaces of the punch (matrix) was performed on an Amada LC-2415a setup. The punch (matrix) was installed on the installation desktop and positioned using a special mandrel that allows you to accurately base the punch (matrix) relative to the axis of the laser beam. Hardening with the flashing of the allowance along the lateral surface was carried out in the following modes: P = 2000 W; £ = 1500 Hz; V = 0.8 m / min. The thickness of the melted allowance was about 0.15 mm.

Finishing, including the fused surface, was performed by grinding. During machining by grinding of the melted surfaces, the final allowance layer of 0.05 mm was removed. The large size of the removed layer reduces the value of the hardened layer and the maximum hardness of the metal of the hardened layer. The study of microsections prepared from witness samples confirmed the presence of a hardened zone along the entire height of the side surface of the punch (matrix). The hardening depth was 220 μm. The maximum microhardness of the hardened metal exceeded the microhardness of hardened steel P6M5 by 200HV.

Based on the work carried out, we can conclude that the task, namely laser hardening with reflowing the allowance along the side surface to the entire height in one pass, is solved.

The present invention is at the stage of pilot research and testing.

Claims (1)

The method of hardening a stamp for punching holes, including machining the blanks of the punch and the matrix with an allowance on the hardened surface, laser hardening with reflow and finishing, characterized in that the allowance is performed on the side surface of the edge, laser hardening is carried out by reflowing the allowance to its entire height by moving the beam along the perimeter of the edge, oriented perpendicular to the front surface, while finishing is performed on the side surface, and in front of the laz By hardening, the punch and die blanks are fixed and positioned.

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