JPH03173749A - Soft magnetic stainless steel for cold forging and its manufacture - Google Patents

Abstract

PURPOSE:To manufacture the soft magnetic stainless steel excellent in magnetic characteristics and corrosion resistance by extremely reducing the content of Si as well as C, N, O, etc., in the compsn. of a ferritic stainless steel, subjecting a billet to hot rolling and annealing, thereafter executing wire drawing at a specified draft and regulating its grain size. CONSTITUTION:A ferritic stainless billet having a compsn. constituted of, by weight, <0.010% C, <0.20% Si, <0.35% Mn, <0.010% S, 11 to 13% Cr, 0.05 to 0.20% A, <0.0070% O and <0.0100% N, furthermore satisfying <0.015% (C+N) and the balance Fe, or instead of S in the above compsn., contg. one or 2 kinds among 0.002 to 0.02% Ca, <0.30% Bi, <0.30% Pb, <0.04% S and <0.04% Se, and when S and Se are included, contg. at least one kind among 0.002 to 0.040% Te and 0.02 to 0.15% Zr or furthermore contg. one or >=2 kinds among <4.0% Mo, <0.5% Cu, <2.5% Ni, <0.20% Nb and <0.20% V is hot- rolled at 850 to 1100 deg.C, is thereafter annealed at 650 to 900 deg.C and is furthermore subjected to 15 to 40% wire drawing to regulate its grain size number to 3 to 6, by which the soft magnetic stainless steel for cold forging can be manufactured.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to soft magnetic steel materials, and more specifically to cold forgeability and shear cutting properties used in magnetic core materials for electronic fuel injection devices, solenoid valves, magnetic sensors, etc. The present invention relates to a soft magnetic stainless steel for cold forging that has excellent properties, magnetic properties, electrical properties, corrosion resistance, and machinability, and a method for producing the same.

[Conventional technology]

Conventionally, iron has been used mostly for magnetic core materials such as electronic fuel injection devices, solenoid valves, and magnetic sensors.

This is because iron has a certain degree of soft magnetism, and has excellent cold forging properties that allow it to be easily cold forged into complex shapes such as the parts used in the above applications, and the manufacturing cost is low, and the material itself is inexpensive. Because there is.

On the other hand, in recent years, there has been a need for products that can be manufactured on current manufacturing lines that use iron, that is, have the same cold forging properties and shear cutting properties as iron, have excellent corrosion resistance, and have even higher performance. Therefore, there has been a demand for soft magnetic steel that has three properties: improved magnetic response.

However, the current technology is stuck at the following points.

One type is steel that is cold-forged and then plated with N1-P to add corrosion resistance. This material has excellent magnetic flux density and cold forgeability (tensile strength 32 kgf/+w+m"
) However, when it was assembled as a component, the plating peeled off during operation, causing the valve to become clogged. Furthermore, the electrical resistance is as low as 15 μΩcm, and the responsiveness is extremely low. In addition, as a soft magnetic steel based on stainless steel,
Currently, Pe-13Cr-I developed in early 1975
Si-0,25Al steel has been used for cold forging for over 10 years. This material has excellent corrosion resistance, high electrical resistance, and excellent responsiveness, but has a tensile strength of 45 kgf/+am.
”, and in terms of cold forging properties, it has a very high tensile strength of 32
kgf/mm! , the limit machining rate of 70%) was not reached. Therefore, cold forging was not possible in the manufacturing process for steel.

After that, although attempts were made to improve the cold forgeability and electromagnetic properties of Fe-13Cr-ISi-0,25AI steel,
No material has been developed that has better cold forgeability than Cr-ISi-0,25AI steel.

In addition, 13Cr-0, which was recently developed for high-cold forging,
1Si has a tensile strength of 38 kgf/i+m, which is somewhat insufficient in cold forging properties, and due to the stickiness characteristic of stainless steel, it has poor shear cutting properties and has problems with manufacturability on iron production lines. be.

[Problem that the invention seeks to solve]

The present invention was made to solve the above-mentioned drawbacks of conventional steel used as magnetic core materials for electronic fuel injection devices, etc., and is required for magnetic core materials for electronic fuel injection devices, solenoid valves, magnetic sensors, etc. tensile strength of 36kgf/Imm" or less,
It has a limit processing rate of 75% or more and has excellent cold forging property and excellent shear cutting performance, which is comparable to that of steel.It also has an electrical resistance of 45 μΩcm or more, exhibiting excellent responsiveness, and has excellent corrosion resistance and magnetic properties. The purpose of the present invention is to provide a soft magnetic stainless steel for cold forging with excellent properties and machinability, and a method for manufacturing the same.

[Means to solve the problem]

In view of the above-mentioned drawbacks of conventional steel, the present inventors have completed the present invention as a result of extensive research into the effects of various alloying elements on the cold forgeability, magnetic properties, electrical resistance, and corrosion resistance of conventional steel. The present invention is based on the following new findings.

With conventional metallurgical methods, the means to obtain cold forgeability comparable to that of iron results in a martensitic structure within the composition range of this alloy, but this time,
It was discovered that a single ferrite phase could be obtained by achieving extremely low CfN, which could not be achieved metallurgically using conventional methods. Furthermore, in this ultra-low C+N ferrite steel, Si, Mn
By reducing the amount of other elements required for manufacturing to the minimum level and cleaning them, we were able to obtain cold forgeability that far exceeds that previously expected.

Conventionally, in the present invention, approximately 0.5% Si has been added for deoxidation, resulting in large solid solution hardening and generation of many inclusions, resulting in considerable deterioration of cold forgeability and magnetic properties. I focused on this. In other words, if AI is used instead of Si as a deoxidizing agent, the deoxidizing power of AI is stronger, so the
．． The addition of a small amount of 0.05 to 0.20% can sufficiently deoxidize, resulting in small solid solution hardening and fewer inclusions, making it possible to successfully obtain excellent cold forgeability that was previously unanticipated. More specifically, as a result of thorough investigation into the influence of alloys on 13Cr stainless steel, it was found that the solid solution hardening per unit weight % is greater in Si than in AI. Therefore, due to the synergistic effect of the above-mentioned difference in deoxidizing power between A1 and Si and this difference in solid solution hardenability, excellent cold forging property that was previously not expected was obtained.

The present invention has obtained a soft magnetic stainless steel with excellent cold forging properties as described above, but in the actual cold forging process, a coiled material is shear cut to form a cold forging base material, and then the cold forging base material is Send it to the forging machine. At that time, the rolled coil of the steel of the present invention was annealed (900
If the material was shear cut at the same temperature (equivalent to ℃ x 2 hours), the material would become too sticky and sag would occur on the cut end surface, causing the shape of the cold forging base material to deform and making it impossible to cold forge. Therefore, the present inventors carefully investigated the influence of composition, material hardness (preliminary processing), and crystal grain size (heat treatment) on cuttability, and as a result, obtained the following new knowledge.

That is, it has been found that when the chemical composition is changed to improve shear cuttability, the cold forgeability deteriorates.

Next, it was discovered that when the wire drawing process of 15 to 40 x was performed as a preliminary process to increase the material hardness, the cuttability was improved and the cold forgeability was not impaired. The figure is a graph of punch surface pressure against processing strain in a restrained compression test of the material (2) as annealed after rolling and the material (2) after 25% wire drawing. As shown in the figure, while the processing strain is small, the punch surface pressure of the material after wire drawing is higher than that of the material that has been annealed after rolling because the influence of the wire drawing hardening that is the preliminary processing remains. However, when the processing strain increases, the punch surface pressure becomes exactly the same as that without wire drawing. That is, by increasing the hardness of the material by wire drawing, it has become possible to improve the cuttability without impairing cold forgeability.

Furthermore, regarding the crystal grain size, it was found that the larger the grain size, the better the cutting performance. However, if the grain size number is 3 or less, it is difficult to obtain uniform grain size, resulting in mixed grains, which makes it impossible to obtain an accurate shape during cold forging, and the surface texture of the cold forged product becomes rough. It was also discovered that when the grain size number is 6 or more, seizure occurs during cold forging. Therefore, we set the grain size number in the range of 3 to 6, which has both properties of cold forgeability and cuttability, and obtained a new finding that the optimum grain size is 3.

The soft magnetic stainless steel for cold forging of the present invention has, as the first invention, co, otoz or less, Si 0.20% or less,
Mn0135% or less, S 0.010% or less, Cr1
1~13X, AI 0°05~0.20%, 00.
0070X or less, N 0.0100% or less, C1N 0
．． 0.015% or less, with the remainder consisting of Fe and impurity elements.

In the second invention, in order to further improve the machinability of the first invention, Ca 0.002 to 0.020χ, Bi 0.30X
Below, pbO0 30% or less, S 0.040% or less, S
When containing one or more of e 0.040% or less, and further containing one or more of S and Se, Te 0.002 to 0.040χ, Zr 0.02 to
It contains one or two of 0.15χ.

The third invention further improves the corrosion resistance of the first invention,
Mo 4.0% or less, Cu 0.50X or less, Ni 2
．． 5% or less, Nb 0.20% or less, and V 0.20% or less.

The fourth invention further improves the corrosion resistance of the second invention by adding Mo 4.0X or less, Cu 0.50X or less, Ni 2
．． 5% or less, Nb 0.20% or less, and V 0.20% or less.

The fifth to eighth inventions include the first to fourth invention steels having 850 to 110
After hot rolling at 0℃, annealing at 650~900℃ and 15~
40χ wire drawing is performed at least once, and the grain size number is set to 3 to 6 to improve shear cutting performance.

Next, the reason for limiting the component composition in the present invention will be explained.

Ci 0.010X or less Carbon is an element that impairs cold forgeability through solid solution strengthening and also has a negative effect on magnetic properties.In the present invention, it is desirable to reduce the amount as much as possible, and the upper limit is set to 0.010X or less.
010χ. In addition, in order to further improve cold forgeability and magnetic properties, it is desirable that the content be 0°005% or less.

Si: 0.20% or less Si is an element that impairs cold forgeability due to its solid solution strengthening effect, and also generates a large number of inclusions, resulting in deterioration of cold forgeability and magnetic properties. Since the most important thing is forgeability, the upper limit was set to 0.20χ.

Mn: 0.35X or less Mn significantly impairs corrosion resistance, magnetic properties, and cold forgeability, so it is preferably 0.10% or less, but in consideration of actual manufacturability, the upper limit was set to 0.35X.

S, 0.010X or less S is contained as an impurity in steel, but since it is an element that impairs cold forgeability, its upper limit was set to 0.010X.

Cr; 11-132 Cr is a basic element that improves corrosion resistance, electrical resistance, and magnetic properties, and if it is not contained at least 11% or more,
Since the effect was not sufficient and excellent corrosion resistance and electrical resistance could not be obtained, the lower limit was set to 11χ.

However, if the content exceeds 13χ, the magnetic properties and cold forgeability will be impaired, so the upper limit was set at 13χ.

Al; 0.05-0.20! AI is a solid solution strengthening element that impairs cold forgeability and also inhibits weldability. However, as a deoxidizing agent, Si
more effective and solid solution hardening per unit weight % than Si
smaller. In order to obtain this effect, it is necessary to contain 0.05% or more, and the lower limit is set to 0.05χ. However, even if the content exceeds 0.202, the deoxidizing effect is saturated and cold forgeability is impaired, so the upper limit was set at 0.20χ.

0, 0.0070% or less Since 0 forms an intrusive solid solution and significantly deteriorates cold forgeability, it is desirable to have as little as possible, but in consideration of actual manufacturability, the upper limit was set to 0.0070χ.

N: 0.0100% or less N is contained in steel as an impurity, but by regulating it to 0.0100% or less, it is effective in improving cold forgeability and magnetic properties, so the upper limit was set as o, oiooχ. .

C+N: 0.015% or less C and N are elements that significantly impair magnetic properties and corrosion resistance, and impair cold forgeability due to solid solution strengthening.

In the present invention, C+N is 0.015% or less, and S
The purpose is to set i to an extremely low level, and even if a small amount of AI is added, it becomes a single ferrite phase, has a tensile strength of 36 kgf/mm" or less, and has excellent cold forgeability with a limit working rate of 75% or more. Therefore, it is necessary to reduce C1N as much as possible, and the upper limit is set to 0.015χ.

S: 0.040X or less, Se: 0.040X or less S, Se is added to improve machinability, but
Since a large amount of content impairs cold forgeability, the upper limit should be set at 0°04.
It was set to 0χ.

Pb: 0.30% or less, Bi: 0.30% or less Pb and Bi are elements that improve machinability, but their inclusion in large amounts impairs cold forgeability, so the upper limit was set to 0.30χ.

Ca H0.002-0.020χ Ca is added to improve machinability, but in order to obtain the above effect, the content must be 0.002% or more. However, if the content exceeds 0.020χ, cold forgeability will be impaired, so the upper limit was set at 0.020χ.

Te 30.002~0.040χ Te has the effect of neutralizing the effects of S and Se on cold forgeability, and to obtain this effect, 0.002% is required.
It is necessary to contain the above amount. However, the upper limit was set at 0°040χ because a large amount of Ni would actually impair cold forgeability.

Zr; 0.02 to 0.15χ Zr is an element that spheroidizes MnS and MnSe and improves cold forgeability, and must be contained in an amount of at least 0.02%. However, since a large amount of content impairs cold forgeability, the upper limit was set to 0.15χ.

Mo: 4.0% or less, Cu: 0.502 or less,
Ni H2, 5% or less, Nb, 0.20X or less, V
, 0.20% or less Mo5Cu, Ni5Nb, V
is an element that improves corrosion resistance. However, Mo is 4.0χ
If the content exceeds 0.50χ for Cu, 2.5χ for Ni, and 0.20χ for Nb and V, the magnetic properties and cold forgeability will be impaired, so the upper limit for Mo is 4.0XS.
Cu is 0.50χ, Ni is 2.5χ, Nb, and V is 0.
It was set to 20χ.

Next, the reason for limiting the manufacturing conditions in the present invention will be explained.

The hot rolling temperature was 850 to 1100°C.
Rolling at temperatures below 1100°C will result in more defects and the crystal grains will become too small, while rolling at temperatures above 1100°C will result in production problems such as grains becoming too large and the billet becoming bent. This is because the above problem occurs.

The annealing temperature was set at 650 to 900°C in order to ensure good cold forgeability and shear cuttability.
This is because if the temperature is lower than 900°C, there is no strain relief effect, and if the temperature exceeds 900°C, the crystal grains become coarse and grain size cannot be obtained.

The wire drawing process was set to 15 to 40χ in order to improve shear cutting properties without impairing cold forging properties.
If it is less than 40χ, the increase in material hardness will be small and the material will be too sticky, and the shear cutting properties will not improve much.If it exceeds 40χ, the material hardness will become too high, and the shear cutting properties will be impaired, resulting in cold forging cracking, etc. There is a risk that
It was set as χ.

〔Example〕

Next, the features of the present invention will be clarified by comparing them with conventional steel and comparative steel through examples.

Table 1 shows these samples. It shows the chemical composition of steel.

(Left below) In Table 1, No. 1 to No. 8 steels are No. 1.5 invention steels, No.
9-15 steel is the 2.6th invention steel, No. 16-25tlij
1 is the 3.7th invention steel, and Nos. 26 to 29 are the 4.8th invention steel. No. 30 to 34 steels are comparative steels, and N035
．． Steel No. 36 is conventional steel, No. 35 is Fe, and No. 36 is Pe-13Cr-ISi-0,25AI.

The test steels in Table 1 were held at 900°C for 2 hours and then subjected to heat treatment at a cooling rate of 100"C/hour.
Tensile strength, limit processing rate, magnetic flux density, coercive force, corrosion resistance, electrical resistance, and machinability were measured.

The tensile strength was measured using a JIS No. d test piece, and the limit workability was determined based on the Cold Forging Subcommittee Standards of the Japan Society for the Working of Plastics and the cold upsetting test method (temporary standard). Then, a compression test was conducted using a test piece with a diameter of 14 mmφ, a height of 211 mm, and a notch, and the crack incidence rate was 5.
The upsetting rate was measured at 0%.

Regarding magnetic properties, a DC type BH) laser was used to test specimens with an outer diameter of 24 pieces and an inner diameter of 16 mm and a thickness of 16 mm.
111 rings were manufactured and the magnetic flux density and coercive force were measured.

Regarding corrosion resistance, we conducted a salt spray test using a 5% NaCl aqueous solution and measured the speech rate.Those with a speech rate of 5% or less are ◎, and those with a speech rate of over 5% to 25% are 0.25% to 50%. Those with a score of Δ and those exceeding 50% with a score of ×.

The electrical resistance was measured by the Wheatstone bridge method using a 1.2 mmφ x 500 mm wire as a test piece.

Regarding machinability, using a 10 mm thick test piece, rotation speed 725 r, p, m, drill SKH 5 mmφ, load 4.
A drilling test was carried out using 1 kg, and the time required to drill the hole was measured.

The measured tensile strength, limit processing rate, magnetic flux density, coercive force, corrosion resistance, electrical resistance, and machinability are shown in Table 2.

(Left below) As is clear from Table 2, the comparison steel No. 30 has a high Cr content, so although it has excellent corrosion resistance,
The tensile strength and limit working rate are inferior, and therefore the cold forgeability is inferior. No. 31 steel has a low Cr content, so its corrosion resistance is very poor, and No. 32 steel has a high AI content, so
It has poor tensile strength and therefore poor cold forgeability.
Because No. 33 steel has a high Si content, it has poor tensile strength, limited workability, and very poor cold forgeability, and is
Since steel No. 34 has a high C1N content, it has poor tensile strength and limited working rate, and therefore has very low cold forgeability and poor corrosion resistance and coercive force.

On the other hand, the conventional steel No. 35 steel corresponds to pure iron and has relatively good cold forgeability, but is inferior in corrosion resistance and coercive force. It has high strength, low limit processing rate, therefore poor cold forgeability, and low magnetic flux density.

In contrast, No. 1 to No. 29 steels, which are the steels of the present invention, have a tensile strength of 36 kgf/mm" or less, a limit workability of 75% or more, excellent cold forgeability, and magnetic flux. It had satisfactory magnetic properties such as density and coercive force, was excellent in corrosion resistance, had high electrical resistance, and had excellent magnetic response, confirming the effects of the present invention.

Next, regarding the shear cutting properties, materials hot rolled at 970° C. were annealed at 720° C., and materials subjected to wire drawing at the processing rates shown in Table 3 were evaluated. That is, after shear cutting, those that could be fed through a normal cold forging line without sagging on the cut surface were evaluated as ○, and those that could not be fed on a normal cold forging line due to sagging on the cut surface were evaluated as x. The results are shown in Table 3.

(Left below) Table 3 As is clear from Table 3, among the steels of the present invention, those with a wire drawing rate of less than 15% all have small work hardening.
Due to the low punch surface pressure, sagging occurs on the end face during cutting, resulting in poor shear cutting performance.Those with a wire drawing rate of over 40% have too much work hardening, and although they have excellent shear cutting performance, cold forging Cracks occur due to this. On the other hand, among the steels of the present invention, those having a wire drawing rate of 15 to 40% had excellent shear cutting properties, confirming the effects of the present invention.

〔Effect of the invention〕

As detailed above, the soft magnetic stainless steel for cold forging and the manufacturing method thereof of the present invention reduce Si to an extremely low level, add a small amount of AI, and solid solution strengthening elements such as C, N, and O. While maintaining excellent magnetic properties, electrical resistance, and corrosion resistance, it improves cold forgeability, and further improves wire drawing processing.
Excellent manufacturability (shear cutting performance) comparable to that of iron due to grain control
is given.

Furthermore, Ca, Bi, Pb, SSSe, Te,
By adding Zr in combination as necessary, machinability is improved without impairing cold forgeability.

The present invention is a corrosion-resistant soft magnetic steel suitable for magnetic core parts manufactured by cold forging such as pulse-operated electronic fuel injection devices and solenoid valves, and has high practicality.

[Brief explanation of the drawing]

The figure shows the relationship between upsetting strain and punch surface pressure.
(2) is a product that has been annealed and peeled after rolling, and (2) is a product that has been annealed and peeled after rolling, and then subjected to a 25% drawing process. The test was a restrained compression test, and the compression speed was 10
mm/win, without lubrication.

Claims (8)

[Claims] (1) C0.010% or less by weight, Si0.20
% or less, Mn 0.35% or less, S 0.010% or less, C
r11-13%, Al0.05-0.20%, O0.0
070% or less, N0.0100% or less, C+N0.01
A soft magnetic stainless steel for cold forging, characterized in that it contains 5% or less, and the remainder consists of Fe and impurity elements. (2) C0.010% or less by weight, Si0.20
% or less, Mn 0.35% or less, Cr 11-13%, Al
0.05-0.20%, O0.0070% or less, N0.
Contains 0.0100% or less, C + N 0.015% or less, and further Ca 0.002 to 0.020%, Bi 0.30% or less, Pb 0.30% or less, S 0.040% or less, Se0
．． 040% or less, and further contains one or more of S and Se, Te0.
A soft magnetic stainless steel for cold forging, characterized in that it contains one or two of 0.002% to 0.040% and 0.02% to 0.15% of Zr, with the remainder consisting of Fe and impurity elements. (3) C0.010% or less by weight, Si0.20
% or less, Mn 0.35% or less, S 0.010% or less, C
r11-13%, Al0.05-0.20%, O0.0
070% or less, N0.0100% or less, C+N0.01
5% or less, and further contains Mo4.0% or less, Cu0.
50% or less, Ni 2.5% or less, Nb 0.20% or less,
Contains one or more of V0.20% or less,
A soft magnetic stainless steel for cold forging, characterized in that the remainder consists of Fe and impurity elements. (4) C0.010% or less by weight, Si0.20
% or less, Mn 0.35% or less, Cr 11-13%, Al
0.05-0.20%O0.0070% or less, N0.0
100% or less, C+N 0.015% or less, and further contains Ca 0.002 to 0.020%, Bi 0.30% or less, Pb 0.30% or less, S 0.040% or less, Se 0.
0.040% or less, and further contains one or more of S and Se, Te0.0
02 to 0.040%, Zr0.02 to 0.15%, and further contains Mo4.0% or less, C
u0.50% or less, Ni2.5% or less, Nb0.20%
A soft magnetic stainless steel for cold forging, characterized in that it contains one or more of the following V0.20% or less, with the remainder consisting of Fe and impurity elements. (5) C0.010% or less by weight, Si0.20
% or less, Mn 0.35% or less, S 0.010% or less, C
r11-13%, Al0.05-0.20%, O0.0
070% or less, N0.0100% or less, C+N0.01
After hot rolling at 850 to 1100°C, steel containing 5% or less and the remainder consisting of Fe and impurity elements has a temperature of 650 to 9
A method for producing soft magnetic stainless steel for cold forging, characterized in that annealing at 00°C and wire drawing at 15 to 40% are performed at least once to give a grain size number of 3 to 6. (6) C0.010% or less by weight, Si0.20
% or less, Mn 0.35% or less, Cr 11-13%, Al
0.05-0.20%, O0.0070% or less, N0.
Contains 0.0100% or less, C + N 0.015% or less, and further Ca 0.002 to 0.020%, Bi 0.30% or less, Pb 0.30% or less, S 0.040% or less, Se0
．． 040% or less, and further contains one or more of S and Se, Te0.
After hot rolling at 850 to 1,100°C,
A method for producing soft magnetic stainless steel for cold forging, characterized in that annealing at 50 to 900°C and wire drawing at 15 to 40% are performed at least once to give a grain size number of 3 to 6. (7) C0.010% or less by weight, Si0.20
% or less, Mn 0.35% or less, S 0.010% or less, C
r11-13%, Al0.05-0.20%, O0.0
070% or less, N0.0100% or less, C+N0.01
5% or less, and further contains Mo4.0% or less, Cu0.
50% or less, Ni 2.5% or less, Nb 0.20% or less,
Contains one or more of V0.20% or less,
Steel consisting of the balance Fe and impurity elements is heated to 850~1
After hot rolling at 100℃, annealing at 650~900℃ and 1
A method for producing soft magnetic stainless steel for cold forging, characterized in that the wire drawing process is performed at least once at a rate of 5 to 40%, and the grain size number is set to 3 to 6. (8) C0.010% or less by weight, Si0.20
% or less, Mn 0.35% or less, Cr 11-13%, Al
0.05-0.20%O0.0070% or less, N0.0
100% or less, C+N 0.015% or less, and further contains Ca 0.002 to 0.020%, Bi 0.30% or less, Pb 0.30% or less, S 0.040% or less, Se 0.
0.040% or less, and further contains one or more of S and Se, Te0.0
02 to 0.040%, Zr0.02 to 0.15%, and further contains Mo4.0% or less, C
u0.50% or less, Ni2.5% or less, Nb0.20%
Hereinafter, steel containing one or more of V0.20% or less and the balance consisting of Fe and impurity elements will be used as 85
After hot rolling at 0 to 1100°C, annealing at 650 to 900°C and wire drawing by 15 to 40% at least once,
A method for producing soft magnetic stainless steel for cold forging, characterized in that the grain size number is 3 to 6.