JPH0791582B2 - Method for manufacturing steel wire for steel wool - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a steel wire for producing steel wool.

[Prior Art] Steel wool is usually produced by drawing a low carbon steel wire rod,
Manufactured by cutting in the longitudinal direction, it is used as a scrubbing brush for general kitchen utensils, rust removal, paint removal, etc., and recently it is also used for disc brakes and composite materials with synthetic resins. Demand is ever increasing.

The characteristics required for steel wire for steel wool production are as follows.

(1) The cutting tool has a long life.

(2) High yield with less generation of fine powder and scraps during cutting.

(3) Steel wool itself has appropriate elasticity and smoothness.

Steel wool is manufactured by cutting as described above, so it has good machinability for steel wire for steel wool production.
That is, a long tool life as shown in (1) is required. Also, the remarkable difference between normal cutting and steel wool cutting is that the part that becomes chips in the former is used as steel wool in the latter, and the chips that become steel wool do not curl and have a stable size. It is indispensable to be able to cut continuously in the shape and shape. In addition, the generation of ultrafine powder and debris (hereinafter referred to as ultrafine cutting debris), which is considered to be desirable in normal cutting, reduces the yield in steel wool production and contaminates the work environment. , It is important to keep to a minimum. Therefore, existing free-cutting steels containing various elements added to improve machinability cannot be used for steel wool production.

At present, as wire rods for manufacturing steel wool, those having higher P and N (Japanese Patent Publication No. 50-14212, US Pat. No. 3387968),
Further, a composite of S and Ca added thereto (Japanese Patent Application Laid-Open No. 55-
No. 6437) is proposed.

On the other hand, in addition to the steel composition, methods for controlling the composition and amount of non-metallic inclusions in steel have also been published. That is, Japanese Examined Japanese Patent Publication 59-33
In 662 publication, in addition to the regulation of steel composition, MnO is mainly
A wire material for steel wool, which is specified to contain non-metallic inclusions containing SiO ₂ , Al ₂ O ₃ and CaO in a wire material cross-sectional area of 5 pieces / mm ² or more, is also disclosed in JP-A-60-24347. In addition to the regulation of steel composition, a wire material for producing steel wool containing 20 ppm or less of Al ₂ O ₃ inclusions of ₃ μm or more has been published. As described above, the results of examining the manufacturing method of the wire material for steel wool from the viewpoint of the steel composition and non-metallic inclusions have been published, but the process of manufacturing the steel wire from the wire material, that is, the drawing process, does not cover the steel wire. The effect on machinability is only slightly described in Japanese Patent Publication No. 50,14212. That is, in the above publication, the wire drawing area reduction rate of 60 to
It has been shown that the twist value decreases at 80%, and as a result, a steel wire for steel wool in which the life of the cutting tool is significantly reduced can be manufactured.

[Problems to be Solved by the Invention] The above conventional wire rod and steel wire both have the effect of prolonging the tool life. "However, there is a limit in terms of the amount of microscopic cutting waste, and there is still room for improvement. large.

It is an object of the present invention to provide a novel method for producing a steel wire for producing steel wool, which is capable of stably achieving a large reduction in microscopic cutting waste, which has not been achieved by conventional materials for producing steel wool. To do.

[Means for Solving Problems] In the present invention, in particular, the combined effect of P and Ca is utilized, and the S and O contents are controlled to sufficiently bring out the effect, and further wire drawing It is a method for producing a steel wire for producing steel wool, which is characterized by controlling a total area reduction rate in a working step, that is, a wire drawing area reduction rate in an appropriate region.

That is, the present invention is C: 0.05 ~ 0.20%, Si: 0.1% or less, Mn: 0.5 ~ 1.5%, P: 0.07
% Or less, S: 0.02% or less, N: 0.003 to 0.01%, O: 0.006 to 0.0
A steel wire rod containing 3% of Ca in the range given by the formula below and the balance of Fe and inevitable impurities
It is a method for producing a steel wire for producing steel wool, which is characterized by performing wire drawing at 80 to 90%.

0.0020- {0.024 x P (%)} ≤ Ca (%) ≤ 0.0040-
{0.024 × P (%)} Next, the reason for limiting the components of the present invention will be described.

C is an indispensable component for imparting appropriate strength and elasticity to steel wool, so 0.05% or more is added, but 0.20%
If it exceeds, the cementite amount becomes excessive and the steel wool becomes brittle, so the upper limit was made 0.20%.

Si is an essential element for deoxidation, but the generation of microscopic cutting scraps increases because non-metallic inclusions increase. Therefore, the upper limit was made 0.1%.

Mn is indispensable as a deoxidizing element of steel, and since it has a remarkable effect of reducing the amount of cementite and homogenizing the structure of the wire, 0.5% or more is added, but if it exceeds 1.5%, the cutting resistance increases, so 1.5 % Was set as the upper limit.

N is usually used in a large amount in free-cutting steel, and N is also increased in the wire material for steel wool production, but similarly to Si, it forms a solid solution with ferrite and makes it brittle, so that the generation of microscopic cutting chips increases. Therefore, the upper limit of N is set to 0.01%. On the other hand, 0.003
If it is less than 0.1%, the surface properties of steel wool are poor and the smoothness is impaired, so the lower limit was made 0.003%.

The present inventors have clarified by many basic studies the influence of mutual relations of P, Ca, S and O described below on the generation of cutting debris, and as a result, the contents of these elements have been determined to fall within appropriate ranges. It was discovered that controlling to 2) produces a remarkable combined effect, and the generation of microscopic cutting chips is greatly reduced.

P improves the surface quality of steel wool like N, but
As a solid-solution strengthening element, it forms a solid solution in ferrite and makes it brittle, so that an increase in microscopic cutting chips cannot be avoided. Therefore, the present inventors have studied the method of reducing the generation of microscopic cutting scraps while maintaining the surface property improving effect of P using the samples of Table 1.

FIG. 1 is a diagram showing the combined effect of P and Ca on the generation rate of microscopic cutting scraps during the cutting of steel wool, and the numerical value shown in the plot in the figure is the generation rate of microscopic cutting scraps. As shown in FIG. 1, by adding an appropriate amount of Ca that depends on the P content, it is possible to newly obtain a low ultrafine cutting waste generation rate as indicated by a numerical value (unit:%) in the figure. discovered. However, if P exceeds 0.07%, the effect of Ca cannot be observed, so the upper limit of P was made 0.07%. P shown in FIG.
If the proper region of Ca is expressed by an equation, equation (1) is obtained.

0.0020- {0.024 x P (%)} ≤ Ca (%) ≤ 0.0040-
{0.024 × P (%)} ……………… (1) In order to fully exert the above-mentioned effects of Ca, Ca reacts with O in the steel and non-metallic inclusions mainly composed of CaO, That is, it is necessary that the inclusions having a composition close to the composition of Rankinite (3CaO · 2SiO ₂ ) are formed from the grenite (2CaO · Al ₂ O ₃ · SiO ₂ ) and that they are finely and uniformly dispersed. For this reason,
The amount of O in steel is 0.006% or more and 0.03% or less.

On the other hand, when there is a large amount of coexisting S, CaS does not sufficiently exhibit its effect because it becomes a CaO-CaS type inclusion in which CaS is precipitated in the cycle of CaO, and in addition, since it produces a large amount of MnS, it is a continuous steel. Wool cannot be obtained. Therefore, the lower the S content, the better, and the upper limit was 0.020%.

Conventionally, a material for steel wool in which Ca and S are added in combination has been disclosed (Japanese Patent Laid-Open No. 55-6437), and in this case, S
Is more than 0.05%. However, when the amount of S is large in this way, non-metallic inclusions mainly composed of CaS cannot be generated, and therefore the excellent effect based on the combined effect of P and Ca referred to in the present invention cannot be obtained. Further, JP-A-60-24347 proposes a material for manufacturing steel wool containing Ca in an amount of 0.008% or less. In this case, Ca is added to enhance the elasticity of steel wool. Yes, P and Ca
This is essentially different from the present invention in which the microscopic cutting waste can be reduced by the combined effect of the above.

In addition, Ca free-cutting steel with Ca added to machine structural steel has already been put to practical use, but most of this type of free-cutting steel is mainly composed of anorthite (CaO ・ Al ₂ O ₃・ 2SiO ₂ ). The composition has been adjusted. Such CaO-based complex inclusions have the effect of adhering to the cemented carbide tool surface and extending the tool life when high-speed cutting of 150 to 200 m / min is performed using a cemented carbide tool containing TiC. It is known. On the other hand, in the present invention, P
The inclusions mainly composed of CaO, which exerts an effect in combination with, have a higher CaO content than anorthite, and the effect is to reduce the amount of microscopic cutting chips.
The effect of Ca in the above Ca free-cutting steel is completely different. The effect of the present invention can be obtained regardless of the cutting tool and the cutting speed.

Next, the reasons for limiting the area reduction ratio of wire drawing in the method of the present invention will be described.

3.1mm by changing the wire drawing area reduction rate from the wire material with composition shown in Table 2.
The steel wire was manufactured, and the relationship between the occurrence rate of microscopic cutting scraps and the wire drawing area reduction rate was investigated. As a result, as shown in FIG. 2, the rate of generation of microscopic cutting scraps is remarkably reduced as the area reduction ratio of wire drawing is increased. According to the prior art, for example, Japanese Examined Patent Publication (Kokoku) No. 50-14212, the wire drawing area reduction ratio of 60 to 80% is optimal, but as shown in FIG. The generation rate of ultrafine cutting debris is still high in the area reduction rate range, and a steel wire for steel wool having a small amount of ultrafine cutting debris can be obtained only by drawing at a total area reduction rate of 80% or more. As described above, it is a fact that it has been unknown for the first time that the reduction ratio of wire drawing significantly affects the generation of microscopic cutting chips and that the optimum range thereof exists. On the other hand, if the wire drawing area reduction rate exceeds 90%, the steel wool becomes brittle and easily breaks, so it is necessary to control it to 90% or less. Based on the experimental results described above, the lower limit of the wire drawing area reduction rate was set to 80% and the upper limit was set to 90%.

[Examples] Steels having the chemical compositions shown in Nos. 1 to 11 in Table 3 were melted in a converter, and billets were partially manufactured by a steel ingot method and the other by a continuous casting method. Wire this It was rolled and conditioned and cooled using a Stelmore cooling facility. After pickling and lubricating the wire, a continuous wire drawing machine was used to produce a steel wire with a diameter of 3.1 mm.

The tool material for cutting steel wool was cemented carbide, and the cutting speed was 54 m / min.

In Table 3, No. 2 is C, No. 3 is Si, No. 4 is N, and No. 5 is S outside the scope of the present invention. From No. 1 to No. 5, C,
The effects of Si, N and S were investigated, and No. 6 and No. 10 are steels in which O is outside the scope of the present invention, and No. 6 to No. 10 are the effects of O. No. 11 is a comparative example, which is a steel wire produced by drawing a conventional wire for producing steel wool that has high P and N, does not contain Ca, and has a low O content at a total area reduction rate of 76.2%.

As shown in Table 3, according to the present invention, the generation rate of microscopic cutting chips is significantly reduced. Further, all the steel wool produced by using the steel wire of the present invention show good characteristics.

[Effect of Occurrence] As described above, according to the present invention, the amount of microscopic cutting scraps generated can be significantly reduced.
It is possible to improve the yield and the working environment.

[Brief description of drawings]

Fig. 1 is a diagram showing the effect of the combined addition of P and Ca on the generation rate of ultrafine cuttings when steel wool is cut, and Fig. 2 is a diagram showing the effect of the wire drawing area reduction rate on the rate of ultrafine cuttings. is there.

Claims (1)

[Claims] 1. C: 0.05 to 0.20%, Si: 0.1% or less, Mn: 0.5 to 1.5%, P: 0.07% or less, S: 0.02% or less, N: 0.003 to 0.01%, O: 0.006 to 0.03% , In addition, it contains Ca in the range obtained by the following formula, and the balance is Fe.
And steel wire rods consisting of unavoidable impurities have a total reduction of 80 to 90.
% Steel wire for steel wool manufacturing process 0.0020-0.024 × P (%) ≦ Ca (%) ≦ 0.0040-0.024 ×
P (%)