JPH0780794A - Clad material for cutlery - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a material for a blade which can be cold-worked by an ordinary rolling mill, is excellent in press punching property, corrosion resistance, polishing property and the like, and is low in cost. [Structure] Austenitic stainless steel with high work-hardness is the center of the plate thickness, and a three-layer clad with stainless steel with low work-hardness stacked on both sides of the plate, and the hardness of the center layer is improved by cold working and tempering. Enhanced clad material for cutlery.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a knife such as a knife, a knife and a rotary blade, a clad material for a cutter and a method for producing the same.

[0002]

2. Description of the Related Art Most conventional stainless steel blades are martensite materials which are hardened by quenching, and precipitation hardening type SUS630 or the like may be used for applications where corrosion resistance is the main purpose and hardness is not so required. Compared to these materials, when austenitic stainless steel having higher corrosion resistance is used as a blade, it is limited to applications such as a paper knife that does not require sharpness. The reason for this is that austenitic materials do not harden by quenching, and hardening by cold working is at most Hv450.
This is because the sharpness is unsatisfactory because it is below the level.

On the other hand, a blade made of martensitic material has the following weak points. Generally has poor corrosion resistance. Sensitive to shock. If the distribution of carbides is not uniform and fine, it may lead to blade spillage and deterioration of corrosion resistance, so countermeasures are necessary. In this situation, one of the inventors of the present invention is Japanese Patent Laid-Open No. 4-2.
46156 describes that temper color, high strength, and high corrosion resistance austenitic stainless steel are suitable as a blade cutter core material (hereinafter, this material will be referred to as NTK H-1).
, See Table 1). This NTK H-1 is H after cold working and subsequent aging treatment (for example, 1 hour at 450 ° C).
It has the characteristics that it can be hardened to v700 or higher and has high corrosion resistance. Conventional work-hardening material SUS3
In the case of 01, 630, and 633, even if the later aging treatment is included, it is at most about Hv450. However, the disadvantage of this material is that the rolling mills that can perform strong cold working are limited, and it is difficult to handle such as cutting and purging when the material after rolling is curled. In the processing, there was a problem that the load of the press was heavy and the casting life of the mold was shortened.

[0004]

DISCLOSURE OF THE INVENTION The object of the present invention is to enable cold working by an ordinary rolling mill, press punchability,
An object of the present invention is to provide a low-cost blade material having excellent corrosion resistance and polishing properties.

[0005]

[Means for Solving the Problems] In rolling, there is friction between the surface of the material and the rolling rolls, and the force required for rolling is a combination of the force originally required to deform the material and the force to overcome friction (rolling of material). Force and frictional force).

Since the present inventors only need to harden the blade portion of the blade, if the central portion of the plate thickness, which is the blade portion, is wrapped with a hard material and the surface is wrapped with a soft material, the frictional force has an effect. The combined force of the force required to stretch near the surface and the frictional force is low, and it can be rolled to a reduction rate that cannot be rolled with a single material with high strength at the center of the plate thickness. The present invention has been completed by finding that (curl) is unlikely to occur, can be easily corrected, and can be easily punched.

That is, according to the present invention, the above-mentioned steel type NTK is used.
With H-1 alone, it was possible to roll from a hot coil with a thickness of 4 mm to a stainless steel Sendzimir rolling machine to a maximum of about 2 mm (50% reduction), but by clad a material with a small work hardening property on the surface, 0.4m
It has become possible to roll up to m (reduction rate 90%).
Moreover, since the whole NTK H-1 is hard, handling such as cutting and purging of the azroll material was difficult.
The clad structure makes it easier to bend and cut, which makes the work in the process after rolling easier. The present invention utilizes austenitic stainless steel having a large work hardening property only in the cutting edge part, and develops a blade material clad with stainless steel having a small work hardening property in the peripheral portion thereof. It became possible to manufacture a blade with high hardness that could not be achieved. The material of the blade is not limited to NTK H-1, and various types of steel can be applied as long as it is an austenitic stainless steel having high work hardening property. As the soft material on the surface, an austenitic material having low internal work hardening or ferritic stainless steel can be used. In many cases, the hardness of the blade portion cannot be satisfied only by work hardening. Therefore, it is generally preferable to further increase the hardness by aging treatment before use. The temperature at this time is usually 350 ° C. or higher and 500 ° C. or lower, but even 600 ° C. is hardened in a short time of several minutes, so 600 ° C. short time is preferable to enhance the efficiency of the aging treatment. The temperature (temper temperature) is 350 to 600 ° C.

[0008]

EFFECT OF THE INVENTION The present invention is superior to the known materials for blades.
In particular, the following points are excellent. Since it is an austenitic stainless steel blade, it is possible to obtain a material that has high corrosion resistance, is viscous, and is unlikely to spill, and has broadened the range of choice for blade users. By giving a large hardness only to the part corresponding to the cutting edge, the cold manufacturability of the material is improved, the material can be supplied at low cost, the press punching property is also excellent in the polishing of the cutting tool, and the cutting tool can be cut at low cost. Manufacturing is now possible. In addition, it is a material that is easy to sharpen even from the viewpoint of a knife user.

[0009]

The present invention will be described in more detail with reference to the following examples.

[0010]

[Example 1] Plate thickness of 28 mm as a material having high work hardening property
X NTM H-1 (width 1 m x length 5 m) (Table 1), and two sheets of NTK D-8 (width 2 m) x width 1 m x length 5 m NTK D-8 (Table 2) as low workability materials on both sides thereof. The surroundings were welded to prepare a hot-rolled material having a thickness of 100 mm x a width of 1 m x a length of 5 m. This was hot-rolled, hot-press bonded, and then rolled into a hot coil of 4 mm. This 5
Cold rolling was carried out in the range of 6 to 90% at 4 levels of reduction. Table 3 shows the hardness of these materials and the hardness when the aging treatment is added. NTK H-1 shows Hv6 at a rolling reduction of 56%.
A high hardness of Hv771 was obtained by applying an aging treatment at 450 ° C. for 1 hour after reducing the pressure to 00 or more and 90%. It is even harder than the maximum hardness 710 obtained with a single material. On the other hand, the soft material NTKD-8 is Hv28
0-381 is soft. These materials are NTK H-1
Although the blade part is harder than the single 50% rolled material, it is soft as a whole, so flatness correction is easy, noise during press punching is low, and polishing for blade attachment is easy. It was

[0011]

[0012]

[0013]

[Table 3]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshihiko Maruoka 1-30 Oyama-cho, Sagamihara-shi, Kanagawa Japan Metal Industry Co., Ltd. Sagamihara Factory (72) Inventor Akira Niimi 1-30 Oyama-machi, Sagamihara-shi, Kanagawa No. Nippon Kinzoku Kogyo Co., Ltd. Sagamihara Factory

Claims (2)

[Claims] 1. A three-layer clad in which austenitic stainless steel having a high work-hardening property is centered on the plate thickness and stainless steel having a low work-hardening property is laminated on both sides of the plate thickness, and the hardness of the central layer is increased by cold working. Clad material for cutlery. 2. The work-hardened material as described above, in the range of 350-60
A clad material for blades that has been tempered at 0 ° C and further cured.