CN112609134A - Novel austenite free-cutting stainless steel material - Google Patents
Novel austenite free-cutting stainless steel material Download PDFInfo
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- CN112609134A CN112609134A CN202011627430.8A CN202011627430A CN112609134A CN 112609134 A CN112609134 A CN 112609134A CN 202011627430 A CN202011627430 A CN 202011627430A CN 112609134 A CN112609134 A CN 112609134A
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B43—WRITING OR DRAWING IMPLEMENTS; BUREAU ACCESSORIES
- B43K—IMPLEMENTS FOR WRITING OR DRAWING
- B43K7/00—Ball-point pens
- B43K7/005—Pen barrels
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
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- E—FIXED CONSTRUCTIONS
- E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
- E05B—LOCKS; ACCESSORIES THEREFOR; HANDCUFFS
- E05B19/00—Keys; Accessories therefor
- E05B19/26—Use of special materials for keys
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
The invention belongs to the technical field of stainless steel materials, and particularly discloses a novel austenite free-cutting stainless steel material which comprises the following components in percentage by weight: less than or equal to 0.15 percent of C, 14 to 17 percent of Cr, 16 to 18 percent of Mn, 0.15 to 0.25 percent of S, and the balance of Fe and inevitable impurity elements. The invention replaces nickel with manganese, improves the manganese content to 16-18%, forms a novel austenitic stainless steel without magnetism and with an elongation rate of about 47% through the optimization of the contents of C, Cr and S elements, can completely replace nickel without affecting plasticity, effectively reduces the cost while obtaining good processing performance, has high strength, good wear resistance and good corrosion resistance, can be used for manufacturing elements with high processing precision requirements such as ball-point pen refills, keys and the like, and has obvious advantages compared with the existing 416 and 303 common sulfur-containing free-cutting stainless steels.
Description
Technical Field
The invention relates to the technical field of stainless steel materials, in particular to a novel austenitic free-cutting stainless steel material.
Background
With the development of the modern industry to the direction of automation, high speed and precision, steel products are required to have good cutting performance, so that the steel products are convenient for automatic cutting machine tool processing, and the production efficiency is improved so as to adapt to mass production. The free-cutting stainless steel is alloy steel which is added with free-cutting elements such as sulfur, phosphorus, lead, calcium, selenium, tellurium and the like singly or compositely to improve the machinability, wherein the proportion of the sulfur-containing free-cutting steel to the total output of the free-cutting steel in the world and China respectively reaches 70 percent and 90 percent, and the free-cutting stainless steel is widely applied to the industrial field with the requirement on the cutting performance.
At present, the common sulfur-containing free-cutting stainless steel types comprise 416 stainless steel and 303 stainless steel, and although both the steels have better cutting performance, certain defects exist. The 416 stainless steel is free-cutting martensitic stainless steel, and comprises the following chemical components in percentage by weight: less than or equal to 0.15 percent of C, less than or equal to 1.25 percent of Mn, less than or equal to 1.00 percent of Si, 12.0 to 14.0 percent of Cr12, less than or equal to 0.6 percent of Ni, less than or equal to 0.06 percent of P, more than or equal to 0.15 percent of S and less than or equal to 0.6 percent of Mo, has good comprehensive mechanical properties, but can not meet the requirement on the plasticity of complex part processing (such as keys and precision parts). The 303 stainless steel is austenite free-cutting stainless wear-resistant acid steel, and comprises the following chemical components in percentage by weight: c is less than or equal to 0.15 percent, Mn is less than or equal to 2.00 percent, Si is less than or equal to 1.00 percent, Cr17.0-19.0 percent, Ni 8.0-10.0 percent, P is less than or equal to 0.20 percent, S is more than or equal to 0.15 percent, Mo is less than or equal to 0.6 percent, and compared with 416 stainless steel, the plasticity and the corrosion resistance of 303 stainless steel are obviously improved, but at least 8 percent of nickel is required to be added, and the nickel is a strong austenite forming element and is very expensive, so that the cost of the steel is high.
Patent application CN101413092A discloses a free-cutting stainless steel 303C, which comprises the following chemical components by weight percent: 0.08-0.12% of C, 12-14% of Mn, less than or equal to 0.8% of Si, less than or equal to 0.03% of P, 0.12-0.15% of S, 13-14% of Cr, 1-2% of Ni and 0.7-1% of Cu, wherein the components of the traditional 303 stainless steel are optimized, the Ni content is reduced, the Mn content is increased, Cu is added to stabilize the austenite structure, and the defects are compensated, but the traditional 303 stainless steel cannot completely replace the Ni, besides high price, the Ni is harmful to human bodies, is easy to cause allergy, has the risk of teratogenesis and carcinogenesis, can limit the application of the stainless steel, and has the plasticity reduction (the elongation of the patent stainless steel is 32% and the elongation [ l1] of the traditional 303 stainless steel is more than or less than 40%) compared with the traditional 303 stainless steel, and the processing.
Disclosure of Invention
In order to solve the problems, the invention provides a novel austenite free-cutting stainless steel material which does not contain nickel element, and has good plasticity, high strength and good corrosion resistance.
In order to achieve the purpose, the invention adopts the following specific technical scheme:
a novel austenite free-cutting stainless steel material comprises the following components in percentage by weight: less than or equal to 0.15 percent of C, 14 to 17 percent of Cr, 16 to 17 percent of Mn, 0.15 to 0.25 percent of S, and the balance of Fe and inevitable impurity elements.
According to the formula, the invention obtains the novel austenitic stainless steel which is non-magnetic, has the elongation of about 47 percent and high tensile strength, and in the technical scheme of the invention, the following factors are mainly considered in component selection and design:
carbon (C): carbon is an austenite forming element and is an effective element for improving the hardness and the strength, the content of the carbon is controlled to be less than or equal to 0.15 percent and exceeds 0.15 percent, stainless steel becomes brittle, the toughness is reduced, the processing performance is reduced, the processing difficulty is increased, and the service life is also influenced.
Chromium (Cr): is an essential element of stainless steel, ensures the corrosion resistance, and forms chromium carbide with carbon to improve the wear resistance of the surface of the material. The invention controls the chromium content to be 14-17%, and the chromium content exceeds 17%, the hardness is increased, and the plasticity is reduced.
Sulfur (S): the steel is added as a free-cutting element, the content is controlled to be 0.15-0.25%, the toughness of the steel is improved when the content is less than 0.15%, the steel is not easy to cut and process, the hot processing difficulty is improved when the content is more than 0.25%, and the stainless steel is easy to crack.
Manganese (Mn): manganese is an austenite forming element, the manganese content of the stainless steel is up to 16-18%, on one hand, the manganese-containing stainless steel is used for replacing nickel to stabilize austenite structure, the strength, the wear resistance and the hardenability of the stainless steel are improved, and the stainless steel has no magnetism; on the other hand, MnS inclusion is formed with S, and MnS is precipitated to block continuity of the structure, so that the cutting performance is excellent; when Mn is less than 16%, the magnetic property is increased, and new austenite can not be formed, and when Mn is more than 18%, crystal grains are obviously enlarged, and the plasticity is in a descending trend.
Preferably, the weight percentage of the Cr is 14-15%.
Preferably, the weight percentage of Mn is 16-17%.
Preferably, the inevitable impurity elements comprise Si, P and O, and the contents of the inevitable impurity elements in percentage by weight are as follows: si is less than or equal to 1.0 percent, P is less than or equal to 0.035 percent, and O is 0.01 to 0.02 percent. The silicon and phosphorus elements have adverse effects on the plasticity of the steel, the content of the silicon and phosphorus elements is reduced as much as possible, and the oxygen and the sulfur have the same family, so spindle-shaped (Fe and Mn) (S-O) composite inclusions can be formed in the steel, the continuity of a matrix is blocked, the cutting performance of the stainless steel is improved, and the abrasion degree of a cutter is reduced.
The invention also provides application of the novel austenite free-cutting stainless steel material, and the novel austenite free-cutting stainless steel material can be used for preparing ball-point pen points or keys with high strength and wear resistance requirements and high processing difficulty.
The invention has the following beneficial effects:
1. according to the invention, the content of manganese is increased to 16-18%, manganese sulfide is formed by combining with sulfur to obtain good cutting performance, more importantly, a novel austenite (without magnetism and with the elongation rate of about 47%) is formed by combining the optimization of the content of C, Cr and S elements and phase transformation, the austenite can completely replace nickel without affecting the plasticity, and the cost is effectively reduced while good processing performance is obtained.
2. Compared with 416 stainless steel, the stainless steel has the advantages of no magnetism, improved plasticity, improved strength and improved corrosion resistance; compared with 303 stainless steel, the stainless steel of the invention can obtain stable austenite structure without adding nickel, and has good plasticity, low cost and high safety.
3. The invention can be used as free-cutting stainless steel, can be used for manufacturing elements with high processing precision requirements, such as ball-point pen refills, keys and the like, and compared with copper keys and copper-plated keys, the keys processed by the stainless steel of the invention have low cost and no pollution.
4. The invention can also add trace auxiliary material components (such as rare earth elements, vanadium elements and the like) on the basis of the existing formula, improves the comprehensive mechanical property, enlarges the application range and has wide application prospect.
Detailed Description
The present invention will be further described with reference to the following specific examples.
The preparation method of the stainless steel sample provided by the embodiment of the invention comprises the following steps: 08F waste steel, micro-carbon ferrochrome (C: 0.1%, Cr: 60%), electrolytic manganese (Mn: 99.9%) and sulfur blocks are used as raw materials, and the raw materials are added into an intermediate frequency furnace for smelting. When the mixed materials are completely melted and the temperature reaches 1570 ℃, removing oxidation slag, adding lime and fluorite for slagging, when the slag is completely melted and has good fluidity, diffusing and deoxidizing silicon calcium powder, and taking a sample in front of a furnace for spectral analysis; adjusting the alloy composition according to the analysis result; adding calcium silicate blocks for precipitation and deoxidation, finally adding pure aluminum powder for final deoxidation, fully stirring, taking a finished product sample, adjusting the temperature to 1595 ℃, and discharging; after the molten steel is poured into a ladle, a heat insulating agent is added for heat insulation and heat preservation, and after argon gas is blown at the bottom for 3 minutes, the molten steel is cast and molded. Hot rolling a steel ingot, wherein the process parameters are as follows: the temperature of the feeding furnace is less than or equal to 600 ℃, the heating temperature is less than or equal to 1200 ℃, the heating time is 4.5 hours, the initial rolling temperature is less than or equal to 1180 ℃, the final rolling temperature is more than or equal to 800 ℃, and the coiled belt is rolled. Annealing, pickling, sanding and cold rolling the hot rolled coiled strip, annealing the coiled strip, cold rolling the coiled strip into coiled strips with various thicknesses, performing final bright annealing, and finally processing the coiled strips into finished products with different specifications as required.
Example 1
A novel austenite free-cutting stainless steel material comprises the following components in percentage by weight: 0.06% of C, 14% of Cr, 16% of Mn, 0.15% of S, 0.35% of Si, 0.022% of P, 0.01% of O and the balance of Fe.
Example 2
A novel austenite free-cutting stainless steel material comprises the following components in percentage by weight: 0.10% of C, 15% of Cr, 17% of Mn, 0.20% of S, 0.50% of Si, 0.031% of P, 0.015% of O and the balance of iron.
Example 3
A novel austenite free-cutting stainless steel material comprises the following components in percentage by weight: 0.15% of C, 17% of Cr, 18% of Mn, 0.25% of S, 1.0% of Si, 0.035% of P, 0.02% of O and the balance of iron.
Example 4
A novel austenite free-cutting stainless steel material comprises the following components in percentage by weight: 0.12% of C, 16% of Cr, 17.5% of Mn, 0.22% of S, 0.68% of Si, 0.018% of P, 0.018% of O and the balance of iron.
Example 5
A novel austenite free-cutting stainless steel material comprises the following components in percentage by weight: 0.08 percent of C, 14.5 percent of Cr, 16.5 percent of Mn16, 0.18 percent of S, 0.54 percent of Si, 0.025 percent of P, 0.013 percent of O and the balance of iron.
Example 6
A novel austenitic free-cutting stainless steel material, the element composition is basically the same as that of the example 2, and the difference is only that: the Cr content was 15.5%.
Example 7
A novel austenitic free-cutting stainless steel material, the element composition is basically the same as that of the example 2, and the difference is only that: the Mn content was 17.5%.
Example 8
A novel austenitic free-cutting stainless steel material, the element composition is basically the same as that of example 1, and the difference is only that: the O content was 0.005%.
Comparative example 1
A novel austenitic free-cutting stainless steel material, the element composition is basically the same as that of example 1, and the difference is only that: the Mn content is 15.6%
Comparative example 2
A novel austenitic free-cutting stainless steel material, the element composition is basically the same as that of example 3, and only the difference lies in that: the Mn content is 18.5 percent
Comparative example 3
A novel austenitic free-cutting stainless steel material, the element composition is basically the same as that of example 3, and only the difference lies in that: the Cr content was 17.4%.
Examples 1-8 and comparative examples 1-3 were tested for properties, wherein the elongation, reduction of area, and tensile strength were determined according to GBT 228.1-2010 part 1 of the tensile test for metallic materials: room temperature test method, the results of the performance tests are as follows:
| item | Elongation A (%) | Reduction of area Z (%) | Tensile strength Rm (mpa) | Magnetic permeability mu |
| Example 1 | 47.7 | 53.6 | 835 | 1.06 |
| Example 2 | 49.8 | 54.3 | 863 | 1.02 |
| Example 3 | 46.9 | 50.8 | 884 | 1.01 |
| Example 4 | 45.0 | 52.3 | 878 | 1.01 |
| Example 5 | 49.5 | 54.1 | 855 | 1.05 |
| Example 6 | 47.2 | 52.6 | 867 | 1.02 |
| Example 7 | 46.3 | 52.9 | 870 | 1.03 |
| Example 8 | 47.0 | 53.4 | 833 | 1.02 |
| Comparative example 1 | 41.2 | 48.1 | 828 | 1.58 |
| Comparative example 2 | 32.6 | 43.8 | 879 | 1.01 |
| Comparative example 3 | 39.6 | 46.2 | 871 | 1.01 |
In conclusion, the stainless steel has good plasticity (the elongation is 45-50%, and the reduction of area is 50-55%);
the strength is high; non-magnetic (mu < 1.3).
This detailed description is to be construed as illustrative only and is not to be taken as limiting the invention, as any changes that may be made by a person skilled in the art after reading the present specification will be protected by the patent laws within the scope of the appended claims.
The traditional 303 stainless steel in the patent is characterized by the elongation rate being more than or equal to 50 percent and the reduction of area being more than or equal to 40 percent;
but in the actual data consulting process, the conventional 303 stainless steel has the elongation rate of more than or equal to 40 percent and the reduction of area of more than or equal to 50 percent;
therefore, 50 is changed to 40 here.
Claims (5)
1. A novel austenite free-cutting stainless steel material is characterized in that: comprises the following components in percentage by weight: less than or equal to 0.15 percent of C, 14 to 17 percent of Cr, 16 to 18 percent of Mn, 0.15 to 0.25 percent of S, and the balance of Fe and inevitable impurity elements.
2. A novel austenitic free-cutting stainless steel material according to claim 1, characterized in that: the weight percentage of the Cr is 14-15%.
3. A novel austenitic free-cutting stainless steel material according to claim 1, characterized in that: the weight percentage of Mn is 16-17%.
4. A novel austenitic free-cutting stainless steel material according to claim 1, characterized in that: the inevitable impurity elements comprise Si, P and O, and the contents of the inevitable impurity elements in percentage by weight are as follows: si is less than or equal to 1.0 percent, P is less than or equal to 0.035 percent, and O is 0.01 to 0.02 percent.
5. Use of a novel austenitic free-cutting stainless steel material according to any of claims 1-4 for the preparation of ball-point pen refills or keys.
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| CN202011627430.8A CN112609134A (en) | 2020-12-31 | 2020-12-31 | Novel austenite free-cutting stainless steel material |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113235019A (en) * | 2021-05-20 | 2021-08-10 | 成都先进金属材料产业技术研究院股份有限公司 | Fe-Mn-Al-N-S series high-nitrogen low-density free-cutting steel bar and preparation method thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001226746A (en) * | 2000-02-10 | 2001-08-21 | Sumitomo Metal Ind Ltd | Manganese alloy steel |
| CN101139686A (en) * | 2007-10-12 | 2008-03-12 | 宁波耀义不锈钢有限公司 | Austenitic stainless steel |
| CN101148740A (en) * | 2007-10-10 | 2008-03-26 | 江苏省方通新型不锈钢制品股份有限公司 | Chromium-manganese-copper-molybdenum series austenite corrosion-resistant wear-proof stainless steel |
| CN101532115A (en) * | 2009-04-16 | 2009-09-16 | 宁波耀义不锈钢有限公司 | Non-nickel austenite stainless steel |
| CN103627976A (en) * | 2012-08-22 | 2014-03-12 | 天津景州不锈钢制品有限公司 | Novel austenitic stainless steel |
| CN105861955A (en) * | 2016-05-31 | 2016-08-17 | 上海大学兴化特种不锈钢研究院 | Economical sulfur-containing free-cutting austenitic stainless steel alloy material |
| CN109628838A (en) * | 2019-01-10 | 2019-04-16 | 福建青拓特钢技术研究有限公司 | A kind of Cutting free, high intensity, high corrosion-resisting austenite stainless steel |
-
2020
- 2020-12-31 CN CN202011627430.8A patent/CN112609134A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001226746A (en) * | 2000-02-10 | 2001-08-21 | Sumitomo Metal Ind Ltd | Manganese alloy steel |
| CN101148740A (en) * | 2007-10-10 | 2008-03-26 | 江苏省方通新型不锈钢制品股份有限公司 | Chromium-manganese-copper-molybdenum series austenite corrosion-resistant wear-proof stainless steel |
| CN101139686A (en) * | 2007-10-12 | 2008-03-12 | 宁波耀义不锈钢有限公司 | Austenitic stainless steel |
| CN101532115A (en) * | 2009-04-16 | 2009-09-16 | 宁波耀义不锈钢有限公司 | Non-nickel austenite stainless steel |
| CN103627976A (en) * | 2012-08-22 | 2014-03-12 | 天津景州不锈钢制品有限公司 | Novel austenitic stainless steel |
| CN105861955A (en) * | 2016-05-31 | 2016-08-17 | 上海大学兴化特种不锈钢研究院 | Economical sulfur-containing free-cutting austenitic stainless steel alloy material |
| CN109628838A (en) * | 2019-01-10 | 2019-04-16 | 福建青拓特钢技术研究有限公司 | A kind of Cutting free, high intensity, high corrosion-resisting austenite stainless steel |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113235019A (en) * | 2021-05-20 | 2021-08-10 | 成都先进金属材料产业技术研究院股份有限公司 | Fe-Mn-Al-N-S series high-nitrogen low-density free-cutting steel bar and preparation method thereof |
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