JPH05504789A - Aluminum-manganese alloy steel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Aluminum-manganese alloy steel Technical field The present invention is characterized in that the ferrite structure is selectively adjusted to the austenite structure. High strength, light weight, low density manufacturer with all alloying elements balanced to It concerns the economical production of gun aluminum alloy steel.

Background technology From iron-manganese-aluminum alloy, low density, oxidation resistance, high strength, and moldability Develop desirable properties such as excellent cold ductility and toughness in service to facilitate It is known that an alloy steel with an austenitic structure can be obtained. small amounts of alloying elements For iron-manganese-aluminum alloys containing No. 405 (Cairns et al.), and No. 3.193,384 (Richards on).

However, the characteristics and hot working characteristics suitable for economical production in conventional steel mills are generally In order to produce an alloy that grows as a property, the crystal structure of the cast alloy to be manufactured must be o Must be done. In other words, it makes it possible to hot-roll alloys and produce products that last for a long time. The body-centered (ferrite) crystal structure in the alloy is It is necessary that the face-centered (austenitic) crystal structure be within the specified range.

It is assumed that these alloys will be used mainly in the form of flat plates, thin plates, and strips.

Hot rolling into these shapes in actual commercial production results in high speed and flattening deformation. Therefore, it is particularly difficult to adjust the ferrite-austenite ratio.

The ferrite-austenite ratio of an austenitic steel alloy is the final characteristic of the alloy steel. is of decisive importance for the properties of the alloy, and its ratio itself depends on the elemental composition of the alloy. . For example, in order for such alloy steel to have excellent oxidation resistance and low resistance to , it is preferable to increase the aluminum content; A ferritic structure is created by However, it is difficult to easily process this ferrite structure at high temperatures using manufacturing methods.

Furthermore, W4 products with high aluminum content have limited formability, and engineers Its usefulness in manufacturing ring structures is limited. With manganese and carbon By adding aluminum, it supplements aluminum and transforms the ferritic structure into austenite. It promotes structural transformation, improves high-temperature processing properties at conventional hot rolling temperatures, and improves formability. It is known that ductility and toughness can be improved, and the structural ratio of austenite is increased. Iron-manganese-aluminum can improve the properties of these products by Although previous research on alloys and methods for making them has been clarified, the elemental composition is How to select the structure to achieve an appropriate ferrite-0-austenite structure ratio. Banarj i published on June 11, 1981. Shiri "The latest iron, manganese, aluminum steel (An Update on Fe -Mn-Al　5teelS)J, the effective alloy composition is 30% manganese, As mentioned above, 9% of aluminum, 1% of silicon, 1% of carbon, and the rest is iron. No indication is given of the range of valid alloy compositions to include, nor is the range of ferrite volumes selected. A useful quantitative relationship between the fractional ratio and the elemental ratio is also the preferred ferrite volume percentage. Applicant also indicates the range of ferrite volume to austenite volume. Accurately adjusting the ratio enables successful hot rolling of iron-manganese-aluminum alloys We found that it is important to

In addition, when the ferrite crystal structure ratio is about 8% at maximum, it is possible to achieve economical and efficient hot rolling. I found out that I can stand up. If the ferrite volume exceeds this ratio, surface damage or "Tension" occurs and the product usually has to be discarded.

Until now, problems caused by alloys with a high proportion of ferrite structure have been addressed by hot pressure Although efforts have been made to lower the rolling temperature, this solution increases rolling costs and This only resulted in an increase in the rolling load of the equipment. In addition, the high rolling temperature Constraining the final minimum size and thickness of the product, so to obtain the required product size , higher ferritic alloys require lower temperatures, but this comes at a cost. This is accompanied by an increase in production costs and the complexity of the manufacturing process.

On the other hand, iron-manganese-aluminum alloys with pure austenitic crystal structure are cast. Formed during the solidification of an ingot or slab, the grains expand during the solidification process. Ru. As a result, the hot working properties are again inadequate. Rolled during hot rolling Irregular damage and cracks on the edges of objects, causing severe edge damage to coils and sheets This leads to cost losses and the market for strips, thin sheets, and coils. You end up with a product that is too small for what you need. For these reasons, this Many austenitic steels that have been available until now have a ferrite crystal structure. is too low to be compatible with today's cost-sensitive continuous slab casting processes. won.

To improve the problem caused by too little ferrite, In order to suppress grain size and crystal expansion during rolling, the casting temperature and Attempts have been made to specially reduce rolling temperatures and/or lower rolling temperatures. But actually As a matter of fact, the need for such a special ylRWI has a negative impact on productivity. (and, in the best case, yield loss and non-specified size) It provides only a limited improvement in product protection.

Disclosure of invention It is an object of the present invention that the volume percentage of the ferrite structure is within the range of about 1% to about 8%. An object of the present invention is to provide a substantially austenitic alloy steel. This alloy has a Nl ratio Aluminum 6% to 13%, manganese 20% to 34%, carbon 0. 2%? 1.4% and 0.4% to 1.3% silicon, with the remainder consisting of iron. child The range of each of these elements is more preferably 6% to 12% aluminum, manganese. 23% to 31%, carbon 0.4% to 1. 2%, silicon 0.　4% to 1.3 %. The volume percentage (VPF) of the ferrite structure of the entire alloy is f < VP F = 32 + 2.6 (A1%) + 5.2 (Si%) - 1,6 (Mn% ) -8, 5 (C%) Selectively by selecting an alloy based on the formula 8 Here, A1%, 81%, Mn%, 0% are respectively It represents the weight ratio of aluminum, silicon, manganese, and carbon, and VPF is ferrite. Represents the volume percentage of the structure. Other elements present as minor impurities may be added to the above formula. does not have a large impact on Additionally, e.g. chromium, nickel, molybdenum , remaining elements such as copper, and other small amounts of impurities are 0. Contains up to 5% , phosphorus may be included up to about 0.11%. Moreover, the amounts of these remaining elements are , less favorable than the volume percentage of ferrite calculated based on the above formula. It has no negative impact.

The above formula should not be applied to M-bases, but rather what is expected in determining the composition of the alloy. should be applied within analytical tolerances that account for analytical variability. Consider tolerances carefully. The experimental format of the above equation considered is as follows.

1 < VPF=32+2. 6 (A1% ± 0.08) + 5.2 (81% ±0. 03)-1,8(Mn%±0.16)-8゜〜5(C%±0.03)< 8 Here, all symbols are the same as defined above.

Opened at Vanderbilt University (Nashville, Tennessee) in June 1981. Presented at the 71st Annual Conference on "Preservation and Replacement Technology for Critical Materials" Samir K-, Benerji, dated June 11, 1981, “Latest Iron-manganese-aluminum 11 (“An Update.

A special alloy described in a paper entitled "Fe-Mn-Al-5teels") are not included in the scope of applicant's alloys. Benerj 2's paper 14 The special alloy seen on the page is 30% manganese, 9% aluminum, and 1% silicon. , contains 1% carbon and the remainder is iron. Mr. Benerj 2 said that the ferrite volume is 100 No mention is made of the preferred range of the fraction, and it is added to the ferrite volume percentage. There is also no mention of the relationship with the specified amounts of alloying elements. But Benerj 2 His earlier paper, apart from the above exclusions, is a special case within the applicant's preferred scope. This is a precise description of the alloy. Mr. Benerj 2 will be granted a certain degree of favorable tolerance. li! In order to provide a Aluminum (9±0.35), silicon (10±0.05)%, carbon (1±0. 05)%. R, W, K, Honeycome's reference paper " According to Steel, Microstructure and Properties J (1981), pages 214-218: We would expect alloys outside the above tolerance range to give acceptable ferrite values. You probably won't be able to do that.

Contains aluminum, silicon, manganese, iron, Mil range required for this invention Although alloy steels are known that have the same weight range for each of these elements (e.g. , Richards On, U.S. Pat. No. 3,193,384), this The prior art is the ferrite-austenite ratio! The relative ratio of each element for one time is There is no disclosure of methods for making alloys selected within these ranges. Book Alloys produced in accordance with the invention must meet two conditions:

That is, (1) aluminum, manganese, carbon, silicon! ! percentage is specified (2) At the same time, the ratio of the amounts of these elements satisfies the above formula. must be achieved.

The alloy produced according to the present invention can be obtained by changing the minimum limit of vPF from 1 to 2. Without changing other parts of the equation, the result is excellent welding properties.

The present invention therefore provides selection criteria for suitable austenitic-alloy steels at relatively low cost. It is provided by the website. These alloys are the most advanced austenitic It has lower density and higher strength than alloy steel, and at the same time has excellent formability and hot workability. and can be manufactured by currently available industrial methods.

To this end, the present invention relies on the relative proportions of ferrite and austenite structures. Well, the conventional W! Enabling commercial production at a reasonable cost with existing technology in steel mill facilities To provide a formula for determining the elemental composition of iron-manganese-aluminum alloys. It is something. These low-grade, high-strength, ductile alloys are easy to melt, cast, and roll. Therefore, shapes and sizes suitable for the purpose of manufacturing ll products can be obtained.

Detailed description of the invention The ferrite-austenite ratio of the bait with the composition in question here is By adjusting the volume percentage of the crystal structure to be in the range of about 1% to about 8%. This results in a very forgiving J114 composition, which is superior to the prior art. Both cold and hot rolling are possible without the problems encountered in I found out that I can become Noh.

In order to investigate the relationship between raw material composition and ferrite-austenite ratio, a laboratory Melting and casting were carried out on a scale with the compositions shown in Table 1 below.

Table 1 Melting number Composition ratio CMn Si At VPF% 1232 0.99 27.8 1.43 9.4 13.0+295 0.9 9 28.8 1.43 9.7 12.71413 0, s2 2s, 7 1 ．． 22 6.9 2.31455 0.85 29. + 1.20 7.7 2 ．． 6+456 0.94 29.7 1.07 9.6 10.81563 0 ．． 82 34.4 1.30 +0.7 4.11568 1.03 2B, 5 0.93 10.2 25.0+887A O,6329,30,759,0 13,8166780,6328,90,789,516,4+667CO,6 329,00,7510,015,5168700,6328,80,7410 ,67,7+667E　O,6229,30,7510,913,41668A O,6829,00,759,811,8166880,6828,80,7 510,18,71868CO,6728,80,7410,93,91668 00,6728,20,7411,16,31668E　O,6628,20, 7411,69,71671A O,9028,20,4 Summer 9.8 6.11 671B O,9028,10,4 Summer 10.1 5.4167ICO,902 7,90,4010,79,316?10 0.88 27.9 0.40 1 1.1 12.81871E O,9027,70,4011,517,817 74＾　0.7+　28.6　0.70　9.9　7.61774B　0.71 2B, 0 0.89 10.6 10.91774CO,6827,90,6 910,911,2177400,7127,90,691+,6 9.7+7 74E　O,7127,80,6812,515,11775＾　0.69　2 ? ,0 0.30 20.9 13.91775B O,7028,10,54 10,914,51775CO,7129,30,8810,79,61774 10,8625,50,6610,217,3177420,5B 25.2 0.68 9.9 1B, 417743 0.74 27.9 0.68 9. 6 8.317752 0.77 27.2 0.29 7.0 1.8277 53 0.73 2B, 5 0,29 9.9 10i1825 0.55 2 7.4 0.4g 11.7 7.91828 0.61 27.9 0.49 +1.7 5.6188OA 0.81 29.5 0.32 7.9 01 881A　O,7629,30,347,50,7188180,7629,3 0,757,52,01881CO,752B,9 1.19 7.5 1.4 18810 0.76 28.6 1.19 7.3 4.61882A O, 8229,10,549,82,8188200,8128,80,549,8 2,81882E 1.06 29.5 0.54 9.2 L, 81882F 1.24 29.3 0.58 9.2 1.7 To create the data in Table 1 Each element and its composition range were selected based on research reported in the literature, density, strength, The influence of these elements on the important properties of oxidation resistance, formability, and weldability. selected based on. The weight of the melt is 50 kg or 70 kg, respectively; Each of these is about 8. 9mm (3.5 inches) or 127mm (5 inches) h) Cast into square ingots. Regarding the sample cast at the same time as this ingot, At the same time, H microscopy and NX measurements are used to analyze the composition of The volume percentage (VPF) of ferrite was investigated.

The ingot is an experimental setup in which it is possible to measure the rolling energy requirements of various alloys. Thickness approx. 8. It was conventionally hot rolled to 35 mm (0°25 inches).

Then, select some of the molten samples and further increase the thickness by about 2. 54mm (0,L 0 inch). Some of the molten compositions contain excess ferrite. There were some items that could not be hot rolled due to the The heating temperature for these operations is 850 ℃ (1560°F) to 1175°C (2150°F)? l-0VP Heating during hot processing of samples with F in the range of 1% to 8% was performed without any problem. It was.

To analyze the compositional data in Table 1 and the corresponding VPF measurements of individual alloys. Therefore, the first order number of weight ratios of carbon, manganese, silicon, and aluminum in the alloy is The VPFO value could be fixedly calculated as follows, and the relationship was confirmed.

That is, 1 < VPF = 32 + 2.6 (A1%) + 5.2 (Si%) - L, S (M n%) -8,5(C%) 8 where A1%, Si%, Mn%, 0% are aluminum, silicon, and manganese present in each of the alloys in the alloy composition; , is the ff1l ratio of carbon, the rest of the composition ratio represents iron, and VPF is the ferrite structure. represents the volume percentage of the structure. This formula works at 315°C (600°C) without undue delay. F) Surfaces of as-cast parts of alloys such as ingots or cast slabs that have been cooled to: The relationship of the independent composition variable to the dependent variable of ferrite volume ratio found in This is what is shown. Applicant shall provide an acceptable level of frequency calculated according to the above formula. It was discovered that elrite is contained in alloys, and at the same time, the alloys can also be used in alloy manufacturing. Aluminum by weight, with composition levels of individual elements that do not exceed the known constraints above. Minium 6% to 13%, Manganese 20% to 34%, Carbon 0.2% to 1.4 %, and 0.4% to 1.3% silicon. In particular, the following A narrower range is preferred. i.e. aluminum 6% to 12%, manganese 23% 31%, carbon 0. 4% to 1.2%, silicon 0. 4% to 1.3% Ru. The proportion of these alloying elements forming the alloy is within the range of VPF 1% to 8%. , select from this range using the above formula so that the remainder has an austenite crystal structure. It will be revealed.

The production of the alloy according to the invention ensures that an acceptable amount of ferrite is present in the crystal structure. The process begins by calculating the composition using the above formula. This formula determines To achieve the required properties of density, strength, toughness, formability, and oxidation resistance within the range of The composition can also be adjusted.

When the manganese content exceeds 30%, a brittle β-manganese phase tends to occur. carbon is about 1. Exceeding 0% has been shown to have a detrimental effect on corrosion resistance.

It has been found that when silicon exceeds about 1.3%, cracking occurs during rolling. Special These additional known limitations and limits that certain elements impose on alloy compositions are The literature and other prior art, shown here as having an impact on the design of alloys for use in It is not intended to exclude other effects mentioned.

Although the manganese content required for these alloys is exceptionally high, it is the only rational and economical The primary source of manganese is usually a manganese-iron alloy. These iron alloys have the following characteristics: It contains about 0.30% to 0.35% phosphorus at maximum. The melting excess of this alloy system Since it is impractical to remove the phosphorus at The iron-manganese-aluminum alloy contains phosphorus in an ff1l ratio of 0.030% to 0.00%. It should contain in the range of 110%, generally about 0.045% to 0.0 It is 55%. The effect of this level of phosphorus on the above equation is not a problem. Main departure The alloys according to Ming are made with small amounts of other materials due to the raw materials used in the melting operations of commercial production. It may also contain elements.

The composition of the alloy is as expected according to the calculations above. The molten metal is at the temperature at which the alloy melts when chosen to achieve the Knight ratio. Heated from approximately 1400°C (2550″F) to 1450°C (2650″F) It will be done.

The alloy of the present invention can be melted by conventional methods such as electric arc or induction furnace. or, optionally, to the “secondary bevel” process used in conventional steel manufacturing. Therefore, it can also be further processed.

This alloy is poured into an ingo butt mold for 2 30 minutes to 3 hours at ambient temperature. Cool and solidify. Coagulation is slightly higher than approximately 1365 (2490’F) The melting and solidification process begins at about 1190°C (2170°F) and ends at about 1190°C (2170°F). The exact temperature is determined by the composition of the elements. Next, remove the ingot from the mold , heat if the ingot needs to be further cooled or reheated for further processing. Add. Alternatively, the alloy of the present invention can be continuously cast into slabs using conventional equipment. can be further reheated and hot rolled according to normal industrial practices. Wear.

In the alloy of the present invention, the problem of phase transition that is characteristic of conventional alloys does not occur. stomach. As long as the ferrite ratio is maintained in the range of about 1% to about 8% as mentioned above, Gots can be hot worked and coiled products can be cold worked without adverse consequences. . Hot rolling of these alloys is traditionally used to process austenitic steels. This can be easily done with equipment. However, the overall alloy content of the composition of the present invention is Determine the heating temperature of the ingot or slab, so that the melting point will be low (if high) (Don't make sure.) As a typical example, if the composition range of the present invention is in the middle, A temperature of 1175°C (2150°F) was found to be sufficient for similar alloys.

The alloy of the present invention can be suitably cold-rolled if necessary, and is suitable for temperature conditions. On the other hand, it tends to behave similarly to conventional austenitic steel.

As mentioned above, the alloy produced according to the present invention has a VPF of between 1 and 8. , was found to develop excellent hot rolling properties. Additionally, welding of such alloys The properties (i.e. resistance welding or arc welding) are also determined by the VPF. I understand. In particular, when VPF takes a value outside the range of approximately 2 to 12, welding characteristics An adverse effect was found on Thus, the properties of the alloy produced by the present invention As such, if good welding properties are expected, the VPF should be in the range between 2 and 8* If it is 2 or less, good results will not be obtained for welding properties. If it is 8 or more, good results in hot rolling properties cannot be obtained. Said The formula is used to select the ratio of alloying elements; in this case, the minimum value of VPF is 1. (Use 2.

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Claims (1)

[Claims] (1) Austems with a predetermined volume percentage of ferrite structure in the range of about 1 to 8%. A night-based alloy steel, the alloy steel contains 6 to 13% aluminum by weight, manga Contains 20-34% carbon, 0.2-1.4% carbon, 0.4-1.3% silicon, and the rest is iron, The ratio of elements forming an alloy with iron selected within the above range is 1<VPF=32+2 ．． 6 (Al% ± 0.08) + 5.2 (Si% ± 0.03) - 1.6 (Mn% ± 0 ．． 16)-8.5(C%±0.03)<8 or is substantially metallurgically equivalent (where Al%, Si %, Mn%, and C% are aluminum, silicon, and magenta present in the alloy, respectively. Ngan represents the weight ratio of carbon, and VPF represents the volume percentage of the ferrite structure. ), the ratio of elements forming alloys with iron is as follows: Manganese is (30±1)%, aluminum is (9±0.35)%, silicon is (1 ±0.05)%, carbon (1±0.05)%, and balance iron a substantially austenitic alloy, characterized in that it is selected such that it does not steel. (2) an orifice in which the predetermined volume percentage of the ferrite structure is within the range of about 1 to 8% by volume; Stenitic alloy steel, wherein the alloy contains 6 to 12% aluminum by weight, Contains 23-31% carbon, 0.4-1.2% carbon, 0.4-1.3% silicon, The rest is iron; The ratio of elements forming an alloy with iron selected within the above range is 1<VPF=32+2 ．． 6 (Al% ± 0.08) + 5.2 (Si% ± 0.03) - 1.6 (Mn% ± 0 ．． 16)-8.5(C%±0.08)<8 or is substantially metallurgically equivalent (where Al%, Si %, Mn%, and C% are aluminum, silicon, and magenta present in the alloy, respectively. Ngan represents the weight ratio of carbon, and VPF represents the volume percentage of the ferrite structure. ), the ratio of elements forming alloys with iron is as follows: Manganese is (30±1)%, aluminum is (9±0.35)%, silicon is (1 ±0.05)%, carbon (1±0.05)%, and balance iron a substantially austenitic alloy, characterized in that it is selected such that it does not steel. (3) (a) The ratio of aluminum, manganese, carbon, and silicon is 1<VPF=32+2.6(Al%±0.08)+5.2(Si%±0.03) -1.6 (Mn%±0.16) -8.5 (C%±0.03)<8 or be substantially metallurgically equivalent to stages and (Here, Al%, Si%, Mn%, and C% are the aluminum present in the alloy, respectively. VPF represents the weight ratio of aluminum, silicon, manganese, and carbon. ), aluminum 6-13%, manganese 20-34%, Selecting the weight ratio from a range of 0.2 to 1.4% carbon and 0.4 to 1.3% silicon, The remainder of the alloy is iron, with additional amounts of (30±1)% manganese and (9%) aluminum. ±0.35)%, silicon (1±0.05)%, carbon (1±0.05)%, and Aluminum, silicon, manganese, (b) the selected ratio of manganese, aluminum, silicon, and carbon; The stage of forming an alloy with iron and iron. A predetermined volume percentage of the ferrite structure composed of is in the range of approximately 1% to 8%. Substantially austenitic, characterized by having hot rollability and formability. A method for producing alloys based on (4) The above weight ratios of aluminum, manganese, carbon, and silicon are Ni 6-12%, manganese 23-31%, carbon 0.4-1.2%, silicon 0. 4. A method according to claim 3, characterized in that it contains 4 to 1.3%, the remainder being iron. (5) a predetermined volume percentage of the ferrite structure is within the range of about 2% to 8% by volume; A stenitic alloy steel, wherein the alloy contains 6 to 13% aluminum by weight, Contains 20-34% carbon, 0.2-1.4% carbon, 0.4-1.3% silicon, The remainder is iron, and the ratio of elements that form an alloy with iron selected within the above range is 2<VPF=32+2.6(Al%±0.08)+5.2(Si%±0.03) -1.6 (Mn%±0.16) -8.5 (C%±0.03)<8 or is substantially metallurgically equivalent (where Al%, Si %, Mn%, and C% are aluminum, silicon, and magenta present in the alloy, respectively. (VPF represents the volume percentage of ferrite structure) , the ratio of elements that form alloys with iron is as follows: manganese is (30±1 )%, aluminum (9±0.35)%, silica (1±0.05)%, carbon is (1±0.05)%, and the remainder is selected so that it is not iron. Substantially austenitic alloy steel. (6) an orifice in which the predetermined volume percentage of the ferrite structure is within the range of about 2 to 8% by volume; Stenitic alloy steel, wherein the alloy contains 6 to 12% aluminum by weight, Contains 23-31% carbon, 0.4-1.2% carbon, 0.4-1.3% silicon, The remainder is iron, and the ratio of elements that form an alloy with iron selected within the above range is 2<VPF=32+2.6(Al%±0.08)+5.2(Si%±0.03) -1.6 (Mn%±0.16) -8.5 (C%±0.03)<8 or is substantially metallurgically equivalent (where Al%, Si %, Mn%, and C% are aluminum, silicon, and magenta present in the alloy, respectively. (VPF represents the volume percentage of ferrite structure) , the ratio of elements that form alloys with iron is as follows: manganese is (30±1 )%, aluminum (9±0.35)%, silicon (1±0.05)%, carbon is (1±0.05)%, and the rest is iron. a substantially austenitic alloy, characterized in that it is selected such that it does not steel. (7) (a) The ratio of aluminum, manganese, carbon, and silicon is 2<VPF=32+2,6(Al%±0.08)+5.2(Si%±0.03) -1.6 (Mn%±0.16) -8.5 (C%±0.03)<8 or be substantially metallurgically equivalent to stages and (Here, Al%, Si%, Mn%, and C% are the aluminum present in the alloy, respectively. VPF represents the weight ratio of aluminum, silicon, manganese, and carbon. 6-13% aluminum, 20-34% manganese, 0 carbon ．． 2-1.4% silicon, 0.4-1.3% silicon, the remainder of the alloy is iron, and man Gun (30±1)%, aluminum (9±0.35)%, silicon (1±0) ．． 05)%, carbon is (1±0.05)%, and the balance is iron. Select the ratio of aluminum, silicon, manganese, and carbon as follows. (b) combined with selected proportions of aluminum, silicon, manganese, carbon and iron; a predetermined volume percentage of the ferrite structure is approximately 2. ~8% by volume and has good hot rolling properties, weldability, and formability. A method of manufacturing a substantially austenitic alloy steel characterized by: (8) The weight ratio of aluminum, manganese, carbon, and silicon is 6-12% manganese, 23-31% manganese, 0.4-1.2% carbon, 0. 8. The substantially organic hydride according to claim 7, characterized in that the amount of A method for producing stenitic alloy steel. (9) (a) The ratio of aluminum, manganese, carbon, and silicon is 1<VPF=32+2.6(Al%±0.08)+5.2(Si%±0.03) -1.6 (Mn%±0.16) -8.5 (C%±0.03)<8 or be substantially metallurgically equivalent to step and (where Al%, Si%, Mn%, C% are respectively present in the alloy) VPF represents the weight ratio of aluminum, silicon, manganese, and carbon. Representing capacity% of light structure) Aluminum 6-13%, Manganese 20-34% , carbon 0.2-1.4%, silicon 0.4-1.3%. , the rest of the alloy is iron, with (30±1)% manganese and (30±1)% aluminum. 9±0.35)%, silicon (1±0.05)%, carbon (1±0.05)%, Aluminum, silicon, manganese so as not to be alloyed with iron and the rest being iron. , choose the proportion of carbon, (b) combined with selected proportions of aluminum, silicon, manganese, carbon and iron; (d) casting the steel into the mold; (e) If the steel is at least red-hot, remove the mold from the steel and bring the steel to ambient temperature. The ferrite structure consists of a cooling hole stage at a temperature of about 1 to 8% by volume. Substantially opaque material that is within the range and has predetermined hot rollability and formability -Production method of stenitic alloy steel. (10) The weight ratios of aluminum, manganese, carbon, and silicon are Luminium 6-12%, Manganese 23-31%, Carbon 0.4-1.2%, Silicon 10. Substantially as claimed in claim 9, wherein the substantially A method for producing austenitic alloy steel. (11) (a) The ratio of aluminum, manganese, carbon, and silicon is 2<VPF=32+2.6(Al%±0.08)+5.2(Si%±0.03) -1.6 (Mn%±0.16) -8.5 (C%±0.03)<8 or be substantially metallurgically equivalent to step and (where Al%, Si%, Mn%, C% are respectively present in the alloy) VPF represents the weight ratio of aluminum, silicon, manganese, and carbon. Representing capacity% of light structure) Aluminum 6-13%, Manganese 20-34% , carbon 0.2-1.4%, silicon 0.4-1.3%, the remainder of the alloy is iron, Furthermore, manganese is (30±1)%, aluminum is (9±0.35)%, and silicon is (1±0.05)% carbon, (1±0.05)% carbon, and the balance iron. Select the ratio of aluminum, silicon, manganese, and carbon to avoid (b) combined with selected proportions of aluminum, silicon, manganese, carbon and iron; (c) casting the steel into the mold; (d) If the steel is at least red-hot, remove the mold from the steel and bring the steel to ambient temperature. The ferrite structure consists of a cooling stage at a temperature of about 2 to 8% by volume. characterized by having predetermined hot rollability, weldability, and formability. A method of manufacturing a substantially austenitic alloy steel. (12) The weight ratios of aluminum, manganese, carbon, and silicon are Luminium 6-12%, Manganese 23-31%, Carbon 0.4-1.2%, Silicon 12. The substantially A method for producing austenitic alloy steel.