JPH1177888A - Stainless clad steel panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the induction heating characteristics of a thin stainless clad steel panel without bringing about the lowering of quality such as the deterioration of corrosion resistance and processability or a marked increase in cost. SOLUTION: In a stainless clad steel panel, a laminating material is composed of stainless steel and a matrix is composed of low carbon steel and the acid soluble Al content of the matrix is set to 0.10-1.5 wt.%. From an aspect of processability, the respective contents of C, Ti and N of the matrix are especially pref. set to 0.02-0.10 wt.%, 0.05-0.60 wt.% and 0-0.010 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stainless steel clad steel sheet suitable as a material for electromagnetic induction heating, such as a material for kitchen products for an electromagnetic cooker.

[0002]

2. Description of the Related Art An electromagnetic cooker indirectly heats an object to be heated by electromagnetic induction unlike direct heating such as resistance heating by gas or a heating wire. Its use is expanding for reasons such as low risk of burns and fire, high thermal efficiency, and environmental friendliness because it does not emit carbon dioxide.

[0003] As materials for kitchen products such as pots and medicine cans used in electromagnetic cookers, thin stainless steel clad steel sheets in which stainless steel is used as a combination material and low carbon steel is used as a base material in view of corrosion resistance and induction heating characteristics, In many cases, a clad thin plate in which stainless steel is used as a bonding material and aluminum or an aluminum alloy is provided as a base material, and the lineup of multilayer clad steel plates having five or seven layers is increasing. Among them, the thin stainless steel clad steel sheet is relatively inexpensive, and is expected to increase in demand in the future with the spread of electromagnetic cookers.

Although the electromagnetic cooker is a safe and clean heating means and has high thermal efficiency as described above, the current technology has a limit in the output of the apparatus, so that the amount of heat itself obtained is inferior to that of a gas range. However, there is a disadvantage that the heating rate is low. In order to solve such problems, it is important to improve the induction heating characteristics of the clad material itself, which is a material for kitchen products, in addition to increasing the output of the apparatus, and in particular, demand is expected to increase in the future It is desired to improve the properties of thin stainless-clad steel sheets.

[0005] However, there has been no history of studying the induction heating characteristics of thin stainless clad steel sheets so far, and it has been mainly related to the fact that the base material crystal grains become coarse near the interface with stainless steel during annealing. It was all over for consideration. That is, in the case of a thin stainless steel clad steel sheet, emphasis is placed on the softening of the stainless steel as the laminated material, and a high temperature (for example, 10
(At least 00 ° C.), this high-temperature annealing causes excessive annealing for the base material low-carbon steel, and as a result, the base material crystal grains become coarse near the interface with the stainless steel. In some applications, orange peel may occur, impairing the surface quality of the product. Improvement of such a problem is the main problem of the related art.
Japanese Patent No. 9916 discloses a method in which the annealing temperature range and the annealing time are limited. Japanese Patent Application Laid-Open No. 62-80223 discloses a method in which hot rolling is performed, followed by rapid cooling and low-temperature winding, followed by annealing at a specific annealing temperature. A technique for preventing coarsening of the base material crystal grains is disclosed. Also, JP-A-62-74025
Japanese Patent Application Laid-Open No. 62-1108 discloses that rapid heating during annealing can suppress the coarsening of crystal grains even at high temperature annealing.
No. 79 discloses a technique for suppressing the coarsening of crystal grains by increasing the N to increase the AlN of the base material. Further, as disclosed in JP-A-61-157637, the base material is C, There is also a technique for avoiding high-temperature annealing by increasing the workability of the base metal side by using a simple ultra-low carbon steel that does not contain a fixed element of N.

[0006] These prior arts are effective techniques when softening of the laminated stainless steel or alternative means are required in response to severe working conditions, but in practice, so severe workability is required. In many cases, the base material crystal grains are remarkably coarsened and become orange peels, so that high-temperature annealing is not required so as to impair the surface quality of the product.

In the case of a thin stainless clad steel sheet, if the base material crystal grains near the interface with the stainless steel are coarse, the crystal rotation of the base material crystal grains or the colony unit of the crystal grains by processing will cause unevenness through the combined material stainless steel. In most applications where processing is not severe, the crystal rotation itself is small, so there is concern about the occurrence of orange peel unless high-temperature annealing is performed so that the base material crystal grains become extremely coarse. No need. Also, even if orange peel occurs, the degree is slight because the processing is not severe, and the orange peel is easily removed in the usual polishing process performed after processing or by slightly increasing the polishing allowance at that time. You.

[0008]

As described above, it is not necessary to pay special attention to the occurrence of orange peel in the normal case. Rather, the spread of electromagnetic cookers and the accompanying demand for thin stainless-clad stainless steel sheets have been increasing. In consideration of the expansion, it is considered more important to improve the induction heating characteristics of the thin stainless clad steel sheet.

However, as described above, there has been no example of examining the induction heating characteristics of a thin stainless steel clad steel sheet, and the induction heating characteristics of a thin stainless steel clad steel sheet have been substantially improved so far. There is no fact. Of course, the base material low-carbon steel, which is a magnetic material, is the main heating element, so the induction heating characteristics are short-circuited, such as by extremely reducing the thickness of the laminated stainless steel to approach the base material low-carbon steel alone. Although a method of improving the short-circuit method is conceivable, such a short-circuit method is not preferable because the induction heating characteristics are improved, but various problems are caused. For example, when the thickness of the laminated stainless steel is extremely reduced, the corrosion resistance is deteriorated, and the contribution of the stainless steel layer to the workability is large, so that the workability is also deteriorated. It may be exposed.

Accordingly, an object of the present invention is to improve the induction heating characteristics of a thin stainless clad steel sheet without causing deterioration in quality such as deterioration of corrosion resistance and workability and a particular increase in cost.

[0011]

Means for Solving the Problems The present inventors have conducted intensive studies on the induction heating characteristics of thin stainless-clad steel sheets and measures to improve them, and as a result, have obtained the following findings. (1) When a thin stainless steel clad steel plate is heated by electromagnetic induction, the base material low carbon steel, which is mainly a magnetic material, generates heat by electromagnetic induction and is heated.The amount of acid-soluble Al contained in the base material low carbon steel With 0.10 higher than normal level
When the content is in the range of 1.5% by weight, the induction heating characteristic is remarkably improved, and the amount of generated heat can be significantly increased under the same magnetization conditions. (2) Generally, the workability deteriorates as the addition amount of the alloy element increases, but in the case of Al, the workability hardly deteriorates unless particularly excessively added.

(3) When the amount of acid-soluble Al is increased as described above, some of the crystal grains of the base material low-carbon steel may be coarsened after cold rolling and annealing. However, in the coarsening of the base metal structure accompanying the high-temperature annealing described above, the base material crystal grains are all coarsened in the vicinity of the interface with the stainless steel, and a coarse-grained layer of the base metal structure is formed immediately below the interface. There is no specific generation site in the coarsening observed when the amount of soluble Al is increased, the generation position is almost random in the thickness direction, and the number of crystal grains to be coarsened is several orders of magnitude in the thickness direction. And less. In the case of the high-temperature annealing, the base metal structure grows to a size of several hundred μm near the interface with stainless steel, whereas when the amount of acid-soluble Al is increased, the high-temperature annealing is not performed. Therefore, only crystal grains of at most about 100 μm are observed, and the degree of coarsening is light.

(4) The coarse particles generated when the amount of acid-soluble Al is increased are relatively small in size and small in number. In addition, since there is no preferential generation near the interface with the stainless steel to form a coarse-grained layer, it does not cause orange peel unlike the coarse-grained particles accompanying high-temperature annealing. However, in rare cases, coarse particles may be concentrated at one location, and in that case, wrinkles may be generated during press molding. To prevent this, the addition of Ti is effective, and the generation of coarse particles can be effectively suppressed by optimizing the amount of Ti.

The present invention has been made based on such findings, and the features thereof are as follows. [1] The joining material is made of stainless steel, the base material is made of low carbon steel, and the content of the acid-soluble Al in the base material is 0.10 to 1.5% by weight.
A stainless steel clad steel sheet. [2] In the stainless clad steel sheet of the above [1], the C content of the base material is 0.02 to 0.10% by weight, the Ti content is 0.05 to 0.60% by weight, and the N content is 0 to 0%. 0.010
A stainless steel clad steel sheet characterized by weight%.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below together with the reasons for limiting the same. The following tests were conducted to clarify the effects of Al and Ti on the induction heating characteristics of thin stainless clad steel sheets and the behavior of coarse grains during annealing.

The components other than Al are almost constant, and the acid-soluble A
l (hereinafter simply referred to as “Al amount”)
A series of low carbon steels varying in the range of 2.5% by weight (Table 2)
And a series of Ti-added low carbon steels (Table 2) in which components other than Al were also substantially constant and only the Al amount was changed in the range of 0.12 to 1.35% by weight. Steel No. B described in Table 1) was used as the base material low carbon steel, and these were combined with the SUS304L equivalent steel shown in Table 1 to obtain thin sheets having different base metal low carbon steels (Ti-free steel and Ti-added steel). Stainless clad steel plate was created. Specifically, Table 1
And a clad slab in which the steel numbers A and B shown in Table 2 were arranged on a base material and a SUS304L-equivalent steel described in Table 2 as a composite material, and these were heated to 1250 ° C .;
Hot rolling at 580 ° C and a winding temperature of 580 ° C to a thickness of 3.4 mm, hot-rolled sheet annealing at 950 ° C, pickling and cold rolling, finish annealing at 900 ° C, pickling and tempering By rolling, a thin stainless-clad steel plate having a total thickness of 0.6 mm made of SUS304L equivalent steel and low-carbon steel (combined material S
US304L equivalent steel arranged on the front and back of base metal low carbon steel 3
The ratio of the thickness of the laminated material to the total thickness of the laminated clad steel sheet: 15% on one side) was prepared, and the induction heating characteristics and the behavior of coarse grains during annealing were investigated.

[0017]

[Table 1]

[0018]

[Table 2]

The evaluation of the induction heating characteristics was performed by forming each thin stainless steel clad steel plate into a pot having a diameter of 18 cm, and measuring the time required for boiling 1 liter of water using a 1400 W electromagnetic cooker using the pot. This time was used as an index of the calorific value, and the quality of the induction heating characteristics was evaluated. Also,
Regarding the state of occurrence of coarse grains due to annealing, the cross section in the thickness direction of the base metal structure of the original sheet before pot forming was observed, and the presence or absence of coarse grains was determined by the presence or absence of crystal grains 2.5 times or more the average crystal grain size. did. Furthermore, the limit drawing ratio (LD
The workability was also evaluated by measuring R).

FIG. 1 and FIG. 2 show the workability evaluated by the calorific value (boiling time of water), the state of generation of coarse grains due to annealing, and the critical drawing ratio obtained in this way. The results are summarized according to the Al content of the low carbon steel and the presence or absence of Ti addition. From these figures, the following points became clear regarding the optimization of the components of the thin stainless-clad steel sheet.

The amount of heat generated during induction heating, that is, the time required to boil 1 liter of water, largely depends on the Al content of the base material low carbon steel, and the Al content is in the range of 0.10 to 1.5% by weight. , The calorific value is greatly increased. Specifically, when the Al content is not in this range, the boiling point is set to 400 to 4
While 50 seconds are required, 3% when the Al content is in the range of 0.10 to 1.5% by weight regardless of the presence or absence of Ti addition.
Boiling occurs in about 00 seconds, and the time required for boiling is greatly reduced.

Although the reason why the calorific value at the time of induction heating greatly depends on the Al content of the base material low-carbon steel as described above is not necessarily clear, the induction heating is performed under the condition that the magnetizing force is constant in the electromagnetic cooker. The calorific value is considered to be proportional to the specific resistance of the base material low-carbon steel, which is a magnetic material, and the magnitude of the magnetic flux excited, that is, the magnetic flux density, and the amount of Al affects the calorific value through these magnitudes. Conceivable. Of course, regarding the magnetic flux density, in addition to the fact that the magnetic flux density of the base material low-carbon steel itself changes depending on the amount of Al, the effect of the back electromotive force due to eddy current, the effect of the specific resistance thereto, and the difference between the laminated material and the base material Although there are many points to be considered such as the problem of magnetic flux distribution and leakage magnetic flux and cannot be simply discussed, the Al content is 0.10.
When it is in the range of 1.5% by weight, both the specific resistance and the exciting magnetic flux density are increased, and it is estimated that the amount of generated heat is greatly increased.

In general, the workability of a steel sheet deteriorates with an increase in the amount of alloying elements. However, as shown in FIG. Evaluation) is not significantly affected, and Ti
Al content of 0.10 to 1.5% by weight with or without addition
In the range, a good limit drawing ratio of about 1.9 to 2.0 can be secured. However, when the Al content exceeds 1.5% by weight, the limit drawing ratio sharply decreases. Here, the fact that the influence of Al on the workability is small is suggested to be related to the fact that the solid solution strengthening ability of Al is small.

As described above, the Al content of the base material low-carbon steel is set to 0.
By controlling the content to 10 to 1.5% by weight, the induction heating characteristics (calorific value) of the thin stainless steel clad steel sheet can be greatly improved while maintaining good workability. The Al content of the carbon steel is set to 0.10 to 1.5% by weight.

Since the improvement of the induction heating characteristic aimed at by the present invention is achieved by optimizing the amount of Al as described above, from the viewpoint of the improvement of the induction heating characteristic, the content of other components is particularly limited. It is not necessary to optimize it, and the component composition according to the components normally used for this kind of base material low carbon steel, that is,
C: 0.01 to 0.20% by weight, Si ≦ 0.5% by weight,
Mn ≦ 1.5% by weight, P ≦ 0.1% by weight, S ≦ 0.03
%, And N ≦ 0.015% by weight.
The balance is substantially made of Fe, so that it does not prevent the inclusion of trace amounts of component elements including unavoidable impurities and the like.
For example, it is possible to add Nb ≦ 0.1 wt% and B ≦ 0.005 wt%. Nb fixes C as Nb carbide, has an effect of suppressing C in the base material from diffusing into the stainless steel for bonding during annealing and deteriorating its corrosion resistance, and B represents a base material during annealing. It has the function of preventing the crystal grains from becoming coarse.

However, as described below, by adding an appropriate amount of Ti and optimizing the amounts of C and N, generation of coarse grains and unnecessary deterioration of workability during annealing can be effectively suppressed.
Better quality is obtained. Although it has already been described that if a large amount of Al is added, the crystal grains of the base material low-carbon steel may become coarse during annealing, but it is true that FIGS.
In the base material low carbon steel (steel No. A group) containing no, generation of coarse grains is recognized in some steels. On the other hand, in the base material low carbon steel containing Ti (Steel No. B group), generation of coarse particles is not recognized at all, and it can be seen that generation of coarse particles can be suppressed by adding Ti.

When Ti is not added, part of Al precipitates as AlN, but during annealing, this becomes coarse and coarse due to Ostwald ripening or the like. This agglomeration and coarsening do not progress evenly in all the crystal grains, and the degree of the agglomeration and coarsening occurs depending on the crystal grains, but when the difference exceeds a certain critical value, the agglomeration and coarsening relatively increase. The grain boundaries of the crystal grains having a reduced pinning force with respect to the advance grain boundary movement start to move in the direction in which the grain growth occurs, and the surrounding crystal grains whose AlN aggregation and coarsening are relatively delayed are used as silkworms. It is presumed that coarsening of crystal grains occurs. At this time, if the amount of Al is large, the size itself of the AlN precipitated first is large, and the progress of agglomeration and coarsening of AlN and the decrease of the grain boundary pinning force occur at an early stage. It is considered that the generation of coarse grains during annealing becomes more evident in comparison.

On the other hand, when Ti is added,
Since N is fixed in its entirety as TiN, AlN does not precipitate, and the base material crystal grains do not become coarse due to the agglomeration of AlN as described above. Further, since TiN is coarsely precipitated at an extremely high temperature, the pinning force against grain boundary movement is inherently weak, and at a temperature of about annealing, there is no aggregation and coarsening more than initially precipitated. It is considered that a difference is caused in the coarsening of the precipitate between the grains, and the resulting difference in the grain boundary pinning force suppresses the coarsening of the crystal grains.

By such an action, A can be added by adding Ti.
It is considered that the coarsening of the base material crystal grains during annealing, which is observed when a large amount of 1 is added, is suppressed. However, an investigation was made on the appropriate amount of Ti to obtain such an effect.
As a result, when Ti is added in the range of 0.05 to 0.60% by weight, the coarsening of the base material crystal grains is effectively suppressed, whereas the Ti content is less than 0.05% by weight. In this case, the effect of suppressing coarsening is not sufficient, and coarsening of the base material crystal grains may occur (this is because when the amount of Ti is insufficient, the size of the precipitated TiN is not sufficient and the TiN
Is thought to be due to additional coagulation and coarsening),
On the other hand, it was found that when the amount of Ti exceeds 0.60% by weight, the workability sharply decreases. For this reason, the base metal low carbon steel
Is added, the amount of addition is 0.05 to 0.60
It is preferably in the range of% by weight.

If the content of C is small, the grain growth itself is improved, and in addition, the α / γ transformation point rises, and the ferrite grain growth continues to a high temperature during annealing, so that the base material crystal grains become coarse. Easy to invite. On the other hand, when the amount of C is excessive, workability is reduced. In order to avoid these problems, the C content is preferably set to 0.02 to 0.10% by weight. N forms nitrides (AlN, TiN) with Al and Ti, but if the amount of N is excessive, the amount of these nitrides generated will also be excessive, resulting in a reduction in workability. To avoid this,
It is preferable that the N amount is 0 to 0.010% by weight (including the case of no addition).

As described above, by controlling the amount of Al, adding an appropriate amount of Ti, and optimizing the amounts of C and N, a thin plate can be formed without causing coarsening of the base material crystal grains and deterioration of workability. The induction heating characteristics of the stainless clad steel sheet can be improved. The present invention is to improve the induction heating characteristics of the thin stainless steel clad steel sheet as a whole by optimizing the components of the base material low carbon steel, which is the main heat generating layer of the thin stainless steel clad steel sheet, has little to do with heat generation. In addition, there is no need to particularly define the composition and thickness (cladding ratio) of stainless steel, which is a composite material that plays only a secondary role even if it is involved, and it may be appropriately selected from the following viewpoints, for example. Can be.

As for the kind of stainless steel used as the bonding material, austenitic stainless steel typified by SUS304 or SUS304L may be used, or SUS4
A ferrite stainless steel such as 30 or a duplex stainless steel of ferrite + austenite may be used. However, if the composite is a ferritic or duplex stainless steel that is a magnetic material, these composites also serve as a heat generating layer in addition to the base material of low-carbon steel, so the composite is a non-magnetic austenitic stainless steel. The effect of the present invention is reduced as compared with the case of

There are no special restrictions on the thickness of the cladding material or the cladding ratio. When importance is placed on corrosion resistance, high-grade appearance, etc., the thickness of the cladding material may be increased. In addition, when the processing is somewhat severe and there is a concern about orange peel due to coarsening of the base material crystal grains in order to raise the annealing temperature, and it is necessary to increase the polishing allowance in the polishing step after molding, it is also necessary to appropriately adjust the bonding material. The thickness may be increased. On the other hand, when cost is important, the thickness of the bonding material may be reduced.

As described above, the thickness of the cladding material and the cladding ratio can be appropriately selected in a usual range. As a preferable range, for example, in a three-layer clad steel sheet in which the cladding material is disposed on the front and back surfaces of the base material, For example, the ratio of the thickness of the composite material to the total thickness may be about 5 to 25% per one side.
If this ratio is less than 5%, the corrosion resistance may be degraded or a part of the base material may be exposed in the polishing step after molding. On the other hand, if it exceeds 25%, the cost of the product increases, meaning the cladding itself. Disappears. For this reason, the ratio of the thickness to the total thickness of the laminated material is approximately 5 to 25% per one side.

As described above, the present invention is to improve the induction heating characteristics of the entire thin stainless steel clad steel sheet by optimizing the components of the base material low carbon steel, which is the main heat generating layer of the thin stainless steel clad steel sheet. Therefore, there is no special restriction on the layer configuration of the clad steel sheet. That is, the present invention is not limited to the three-layer clad steel sheet exemplified above, but can be applied to, for example, a multi-layer clad steel sheet having five or more layers. Further, as a final product, a clad thin plate made of stainless steel and aluminum or an aluminum alloy is used. And a thin stainless steel clad steel sheet according to the present invention.

In the above description, the case where the function and effect of the present invention is used as a material for a kitchen product for an electromagnetic cooker has been described as an example, but the use of the thin stainless steel clad steel plate of the present invention is for a kitchen product used in an electromagnetic cooker. It is not limited to a material, and can be widely used as a material for general articles to be subjected to induction heating, and also as a material for articles for other uses.

As for the improvement of the induction heating characteristics by the addition of Al, Japanese Patent Application Laid-Open No. Hei 8-209308 discloses that a stainless steel plate (not a clad steel plate but a single stainless steel plate) used for an inner pot of an electromagnetic induction heating type rice cooker is disclosed. It is disclosed that when the Al content is increased to 2.5 to 10% by weight to increase the specific resistance, rice is cooked uniformly and evenly. However, this technology is not a thin stainless steel clad steel sheet, but an attempt to improve the induction heating characteristics of a stainless steel sheet alone, and to improve the induction heating characteristics of a thin stainless steel clad steel sheet made of stainless steel and low carbon steel. The object is different from the present invention. In addition, the effect of the technique is to improve the uniformity of rice cooked, and does not make it possible to increase the calorific value as in the present invention. Further, as is apparent from FIG. 1, in the thin stainless clad steel sheet to which the present invention is applied, when the Al content of the base material low carbon steel is increased to a high level such as 2.5 to 10% by weight, the heat generation is rather increased. Will decrease.

[0038]

EXAMPLE A clad slab in which SUS304L equivalent steel shown in Table 1 was used as a laminated material and steel numbers C to Q shown in Table 2 were arranged on a base material was assembled. After heating these to 1250 ° C., the finishing temperature was 950 ° C. Hot rolling at a winding temperature of 610 ° C. to a thickness of 4.0 mm, hot-rolled sheet annealing at 930 ° C., pickling and cold rolling, finish annealing at 920 ° C., pickling and temper rolling By doing so, a thin stainless clad steel sheet of 0.8 mm in total thickness composed of SUS304L equivalent steel and low carbon steel (a three-layer clad steel sheet in which the SUS304L equivalent steel is disposed on the front and back surfaces of the base material low carbon steel, The ratio of material thickness: 10% on one side) was prepared, and the induction heating characteristics of these clad steel sheets, the occurrence of coarse grains during annealing, and the limit drawing ratio (LDR) were investigated.

The evaluation of the induction heating characteristics was performed by forming each thin stainless-clad steel plate into a pot having a diameter of 18 cm, and measuring the time required to boil 1 liter of water using a 1400-w electromagnetic cooker using the pot. This time was used as an index of the calorific value, and the quality of the induction heating characteristics was evaluated. Also,
Regarding the occurrence of coarse grains due to annealing, observe the cross section in the thickness direction of the base metal structure of the original sheet before forming the pot, and determine whether or not coarse grains are generated by the presence or absence of crystal grains 2.5 times or more the average crystal grain size. did.

Table 3 shows the results. According to this, in the present invention example (No. 1 to No. 11 using base steel numbers C to M) in which the Al content of the base low carbon steel falls within the range of the present invention, the boiling point of water is The time required is as short as about 300 seconds, and excellent induction heating characteristics (calorific value) are obtained. In addition, No. 1 using the base material steel number L. No. 10 and No. 10 using base steel number M.
Except for No. 11, the limit drawing ratio was as high as 1.90 to 2.05, and the workability was excellent. In addition, in the examples of the present invention, those in which an appropriate amount of Ti was added to the base material low-carbon steel (base material steel numbers I, J,
No. K using No. K 7-No. In 9), generation of coarse grains is not observed at all. On the other hand, in the case of No. 10
And No. using base metal number M. In No. 11, although the Al content is within the range of the present invention, the former has a higher C content, and the latter has a higher N content than the desired ranges, so that the critical drawing ratio is 1.8.
It has a slightly lower value of 0.

On the other hand, in the comparative example (base metal No. N, O, P
o. 12-No. In 14), the time required for boiling water is as long as 390 to 450 seconds, and the induction heating characteristics are inferior. In addition, the Al. In the case of No. 14 (base metal No. P), the limit drawing ratio was significantly reduced to 1.65. Although the amount of Al is within the range of the present invention, the Al. Also in Comparative Example No. 15 (base material steel No. Q), the critical draw ratio was significantly reduced to 1.65, which caused a problem in workability.

[0042]

[Table 3]

[0043]

According to the present invention described above, the generation of wrinkles at the time of processing due to the coarsening of the base material crystal grains at the time of annealing, the deterioration of workability itself, and the deterioration of quality such as the deterioration of corrosion resistance. The induction heating characteristics of a stainless steel clad steel plate subjected to electromagnetic induction heating as a raw material of a kitchen product for an electromagnetic cooker can be effectively improved without inducing.

[Brief description of the drawings]

FIG. 1 is a graph showing the effect of the acid-soluble Al content of a base metal low carbon steel and the presence or absence of Ti on the induction heating characteristics of a stainless clad steel sheet and the coarsening of base metal grains.

FIG. 2 is a graph showing the influence of the acid-soluble Al content of a base metal low carbon steel and the presence or absence of Ti on the workability of a stainless clad steel sheet and the coarsening of base metal grains.

Claims (2)

[Claims] The composite material is made of stainless steel, the base material is made of low carbon steel, and the base material has an acid-soluble Al content of 0.10-1.
A stainless clad steel sheet characterized by being 5% by weight. 2. The base material has a C content of 0.02 to 0.10% by weight, a Ti content of 0.05 to 0.60% by weight, and an N content of 0 to 0.010% by weight. The stainless steel clad steel sheet according to claim 1, wherein: