CN101413091B - Novel easy-to-cut stainless steel 303B and manufacturing method thereof - Google Patents

Novel easy-to-cut stainless steel 303B and manufacturing method thereof Download PDF

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CN101413091B
CN101413091B CN2008102355328A CN200810235532A CN101413091B CN 101413091 B CN101413091 B CN 101413091B CN 2008102355328 A CN2008102355328 A CN 2008102355328A CN 200810235532 A CN200810235532 A CN 200810235532A CN 101413091 B CN101413091 B CN 101413091B
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content
percent
stainless steel
steel
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CN101413091A (en
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冯爱新
曹宇鹏
董增武
赵光伟
王洋
王雷刚
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Jiangsu University
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Abstract

The invention relates to the field of metallurgy and material science, in particular to a novel free-cutting austenitic stainless steel and a production method thereof. The free-cutting stainless steel comprises the following chemical compositions in mass percentage: 0.08 to 0.15 percent of C, 10 to 11 percent of Mn, less than or equal to 0.8 percent of Si, less than or equal to 0.03 percent of P, 0.12 to 0.15 percent of S, 13 to 14 percent of Cr, 3 to 4 percent of Ni, 0.3 to 0.6 percent of Cu, the balance being Fe and inevitable trace impurity elements. The production method is mainly characterized in that the content is controlled and elements are added according to the composition proportion in the smelting process. The product has the advantages of hardness, corrosion resistance and free cutting. The production method has low cost, and the cost is reduced by more than 20 percent compared with like products in the condition of meeting the prior corrosion-resistant requirement.

Description

Novel easy-to-cut stainless steel 303 B and manufacture method thereof
Technical field
The present invention relates to metallurgy and material science, the invention discloses a kind of novel free-cutting austenitic stainless steel and production method thereof.This steel grade has high toughness and plasticity, cheap, stable performance, is easy to machine-shaping, yield rate advantages of higher.Be specially adapted to make stainless steel materials, band, silk material, bar and other metal products of various descriptions.
Background of invention
303 stainless steels are a kind of base mateirals very widely of using in industrial production.Especially electronic industry, most electronic components need the stainless material of excellent performance to carry out process for processing, but there are some problems again in traditional 303 austenitic stainless steels itself.At first China is the country of a nickel resources shortage.And 303 traditional austenitic stainless steels will reach the nickel content of 8-9%, and this impels China's 303 stainless costs high always; Secondly; 303 traditional stainless steels magnetic may occur in heat treated process; in case take place huge for the stable harm of electronic product performance. last; often volume is very little to be applied to the part of electronic product; this just requires material therefor to possess good free-cutting machinability; thereby the protection cutter improves working (machining) efficiency.In sum, be badly in need of a kind of low price at present, nonmagnetic, free machining stainless steel substitutes 303 traditional stainless steels.
Summary of the invention
The purpose of this invention is to provide a kind of novel easy-to-cut stainless steel and production method thereof.Adopt this novel stainless steel, under the situation that satisfies original anti-corrosion type needs, cost reduces more than 20% than like product.Surface smoothness after processing speed and the processing is better than the SUS303 of Nippon Standard greatly, and exhausted magnetic excellence.
303B of the present invention is the free cutting stainless steel that contains sulphur, comprise following component by mass percentage: C 0.08-0.15%, Mn10-11%, Si≤0.8%, P≤0.03%, S 0.12-0.15%, C г 13-14%, Ni 3-4%, Cu 0.3-0.6%, all the other are mainly Fe and inevitable micro impurity element.
Produce the method for above-mentioned said easy-to-cut stainless steel 303 B, comprise smelting, cast, blank forging rolling and the heat treated step of blank forging rolling spare, it is characterized in that, in smelting process, may further comprise the steps:
(1) melting period when electric furnace just refines and oxidation initial stage, the oxidation molten steel fully takes off P, accounts for total steel quality≤0.03% until the content of P; Desiliconization makes the content of silicon account for total steel quality≤0.80%;
(2) reduction period deoxidation, transfer S, the content of S is controlled at accounts within total steel quality 0.12-0.15%;
(3) add alloying element: by bath analysis, adjust the content of manganese, copper, chromium, nickel, thereby make the mass percent of manganese reach 10-11%, the mass percent of copper reaches 0.3-0.6%, the mass percent of chromium reaches 13-14%, and the mass percent of nickel reaches 3-4%.
(4) when refining furnace is smelted, carry out decarburization, degasification and fine setting alloying element; Just the molten steel after the refining enters the vacuum refinement of VOD stove, and evacuated time is no less than 8 minutes, and vacuum tightness is not more than 1.5mbar, reaches content<30ppm, the content<80ppm of nitrogen, the content<2.5ppm of hydrogen of oxygen.
In production method of the present invention, except that press component ratio adjustment control component concentration in smelting process, all the other processes all can adopt routine operation, for example:
When cast, can adopt the covering slag method of making a bet to pour into a mould;
During the blank forging rolling: when finishing moulding with original blank, its forging ratio K 〉=5, it is 1000-1100 ℃ that the beginning is rolled temperature, in this temperature range, be incubated, soaking time one hour, after soaking time arrives, beginning edging, it is 930 ℃ that finish-forging rolls temperature;
The thermal treatment of blank forging rolling spare: annealing temperature is 950 ℃, and heat-up rate is controlled at 100-180 ℃/min, is incubated in this temperature range, and soaking time is according to the net thickness of workpiece, and considers batch, formulate behind the charging mode, soaking time to after the air cooling of coming out of the stove.
Compare according to the 303B stainless steel of above-mentioned chemical ingredients and production method production and the SUS303 stainless steel of Japanese JIS standard, add micro-Cu unit and usually guaranteed solidity to corrosion, the one-tenth that while 303B austenitic stainless steel has the low Ni of high Mn is grouped into, adopt cheap manganese to replace expensive nickel, greatly reduce production cost.
Its chemical ingredients relatively sees Table 1
Table 1 chemical ingredients comparison sheet (%)
C Mn Si S Cr Ni Cu
303B 0.08-0.15 10.00-11.00 ≤0.80 0.12-0.15 13.00-14.00 3.00-4.00 0.3-0.6
SUS303 ≤0.15 ≤2.00 ≤1.00 ≤0.15 17.00-19.00 8.00-10.00 ------
The 303B stainless steel has following characteristics:
1, this new steel grade has been abandoned traditional generation martensite or has been formed carbide and nitride strengthening means, and adopt formation that stable austenite is arranged and replenish with elements such as Cu, Mn that to strengthen is main means, the thermal treatment by science makes it to have stable austenite phase constitution.
One of characteristic is that adding Cu:Cu itself is a harmful element, but the Cu that adds trace can embody following advantage: in course of hot rolling, Cu can produce the precipitation strength phase in the austenite crystal boundary region, be in the hot rolled initial period this moment, austenite one facial disfigurement one side is recrystallize rapidly, produce the useful intermetallic compound of rich Cu in the distortion, become the central strengthening phase of austenite, the steel after hot rolling presents good intensity.In addition, the corrosion resistance of Cu itself is fine, adds the Cu element, facts have proved and has also improved the resistance to corrosion of this steel grade in dilute sulphuric acid and dilute hydrochloric acid.
Two of characteristic is raisings of high Mn:Mn content, has stablized austenite structure, has effectively avoided the magnetization phenomenon in the thermal treatment.
Three of characteristic is that a little higher than common stainless steel of C content: C is 30 times of Ni for the ability that enlarges austenite region with respect to Ni, so played the effect that replaces Ni element stable austenite.(general stainless steel requires low C, is to improve solidity to corrosion in order to protect Cr, still, in weak corrosive environment, tends to carbon to reduce cost for nickel.)
2, because belong to free-cutting steel, be applicable to that self-acting lathe, digital control processing make the hardware of electric miscellaneous goods, in the course of processing, the wearing and tearing of cutter are less, and the stock-removing efficiency height has reduced cost.
3, with low cost, under the situation that satisfies original anti-corrosion type needs, cost reduces more than 20% than like product.
Description of drawings
The structured flowchart and the description of drawings of specific embodiments of the invention are as follows:
Fig. 1, smelting technology flow process:
1-batching 2-electric furnace 3-melting period 4-5-oxidation period reduction period 6-tundish 7-refining furnace 8-A-in refining period charging B-fusing C-dephosphorization D-desiliconization E-deoxidation (precipitation adds the combined deoxidation method of diffusion) F-transfers sulphur (transferring sulphur by the sulphur iron that adds sulfur-bearing 26%) J-to add alloying element H-decarburization I-degasification G-fine setting alloying element K--tapping
Fig. 2 manufacturing process flow
1-casting 2-steel billet polishing 3-annealing furnace 4 milling train 5-annealing furnace 6-aligning 6-aligning 7-pickling 8-is not in the mood for car (surface peeling fast) 9-centreless grinding 10, check
The process route chart of the process route chart B-pole of A-angle steel, band steel and square steel
Fig. 3,303B energy spectrum analysis
Fig. 4,303B metallograph
Embodiment:
Below in conjunction with example the present invention is done next step description.
Embodiment 1:
Select for use following quality percentage composition to smelt: C 0.10%, Mn 10%, Si≤0.8%, P≤0.03%, S 0.15%, Cr 14%, Ni 3%, Cu 0.4%, all the other are mainly Fe and inevitable micro impurity element.
Concrete Production Flow Chart is described below as shown in Figure 1:
1, charging (as among Fig. 11, A): pressing against iron alloy etc. with waste stainless steel, smear metal and high-carbon is main charge composition.Except carbon, silicon, sulphur, should be near the standard analysis of grade of steel.
2, refining just:
(1) melting period and oxidation period (as among Fig. 11,5): after charging is finished, the beginning heat fused.
1. dephosphorization (as C among Fig. 1), the abundant dephosphorization of oxidation molten steel makes the content of phosphorus account for total steel quality≤0.03%;
2. desiliconization (as D among Fig. 1) makes the content of silicon account for total steel quality≤0.80%;
(2) reduction period (as among Fig. 1 4): main task is oxygen and the sulphur in the regulation and control molten steel, and adds alloying element according to bath analysis.
1. deoxidation (as E among Fig. 1), we adopt precipitation to add the method that spreads combined deoxidation.Main operation is: all skim, add thin slag charge, change and add calcium carbide or carbon dust etc. behind the thin slag and reduce, when slag change white or greyish white after, fully stir, then the sampling analysis composition.In reduction process, keep white slag;
2. transfer sulphur (as F among Fig. 1), concrete grammar is that the sulphur iron that adds sulfur-bearing 26% is transferred sulphur, makes the mass percent of sulphur reach 0.15%, and the chemical combination of removing sulphur is mingled with;
3. add alloying element (as J among Fig. 1): mainly be by bath analysis, adjust the content of manganese, copper, chromium, nickel, thereby make the mass percent of manganese reach 10%, the mass percent of copper reaches 0.4%, the mass percent of chromium reaches 14%, and the mass percent of nickel reaches 3%.3, refining (as among Fig. 1 7): main task is at vacuum decarburization, alloying constituent fine setting under vacuum stripping and the vacuum.
1. decarburization (as H among Fig. 1) guarantees that under vacuum carbon content is controlled at 0.1% of total steel quality, adds reductive agent afterwards, with the chromic oxide (Cr in the reducing slag 2O 3), take off O and remove inclusion.
2. degasification (as I among Fig. 1): carry out vacuum refinement by changing the VOD stove behind the tundish over to, the pumpdown time is no less than 8 minutes, and vacuum tightness is not more than 1.5mbar, reaches content<30ppm, the content<80ppm of nitrogen, the content<2.5ppm of hydrogen of oxygen.
3. finely tune alloying element (as G among Fig. 1): carry out bath analysis once more, the content of fine setting manganese, copper, chromium, nickel makes and reaches the composition requirement.
4, cast (as among Fig. 2 1): after 1500 ℃ of tappings, adopt the covering slag method cast of making a bet.
5, dead head, joint flash and burr (as among Fig. 2 2) are removed in casting falling sand and sand removal.
6, high temperature annealing: send heat treatment furnace heating, standby hot rolling blank forging rolling spare behind (as among Fig. 2 3) casting.Thermal treatment process is: annealing temperature is 950 ℃, and heat-up rate is controlled at 100-180 ℃/min, is incubated in this temperature range, and soaking time is according to the net thickness of workpiece, and considers batch, formulate behind the charging mode, soaking time to after the air cooling of coming out of the stove.
7, hot rolling (as among Fig. 2 4): hot rolling technology is: it is 1080 ℃ that the beginning is rolled temperature, in this temperature range, is incubated, and soaking time one hour, after soaking time arrives, beginning edging, it is 930 ℃ of forging ratio K 〉=5 that finish-forging rolls temperature.(Φ 125mm before rolling rolls back Φ 25mm)
8, low-temperature annealing (as among Fig. 2 5): METAL HEATING PROCESS to recrystallization temperature (600 ℃-650 ℃), to eliminate sclerosis, is recovered plasticity.
9, adopt pressing machine that bar is carried out hot straightening (as among Fig. 2 6).
10, for bar (as B among Fig. 2):
1., do not remove bar surface scale (as among Fig. 2 8) with being in the mood for lathe.
2., adopt centerless grinding machine corase grind outer round surface (as among Fig. 2 9).
Adopt the chlorohydric acid pickling (as A, 7 among Fig. 2) of 10%-20% for angle steel, band steel and square steel.
11, check (as among Fig. 2 10).
With the above-mentioned energy spectrum analysis of 303B stainless steel such as Fig. 3 that makes, metallograph as shown in Figure 4.The SUS303 stainless steel of this product and Japanese JIS standard compares, and hardness is corrosion-resistant, and free cutting property is simultaneous test data such as table 2 relatively.
Table 2 performance comparison
Annotate 1. solidity to corrosion employing salt spray corrosion test evaluation, use 5% neutral salt solution, 35 ℃ of temperature, air inlet is pressed and is 35kPa, and going out air pressure is 60kPa, and the time that 303B experiences when specimen surface occurs at dark-coloured is 100 hours.
2. the machinability classification is referring to Han Rongdi, and Yu Qixun is outstanding. cutting of hardworking material processing. and Beijing Machinery Industry press, 1996.
Embodiment 2
Production stage is identical with embodiment 1, difference is, select for use following quality percentage composition to smelt: C 0.08%, Mn 11%, Si≤0.8%, P≤0.03%, S 0.12%, Cr 13%, Ni 4%, Cu 0.6%, all the other are mainly Fe and inevitable micro impurity element.Press above-mentioned composition controlled contents and add element in the smelting phase.Gained 303B stainless steel performance is substantially the same manner as Example 1.
Embodiment 3
Production stage is identical with embodiment 1, difference is, select for use following quality percentage composition to smelt: C 0.15%, Mn 10%, Si≤0.8%, P≤0.03%, S 0.12-0.15%, Cr 13-14%, Ni 3-4%, Cu 0.3%, all the other are mainly Fe and inevitable micro impurity element.Press above-mentioned composition controlled contents and add element in the smelting phase.Gained 303B stainless steel performance is substantially the same manner as Example 1.
By the 303B stainless steel of above-mentioned production, its chemical ingredients, mechanical property etc. all satisfy the technical qualification of consumer electronic products, and the chemical ingredients of its sample and mechanical property detect as 1 and table 2 through detection department of country.

Claims (2)

1. free cutting stainless steel, it is characterized in that, its chemical ingredients comprises following component by mass percentage: C 0.08-0.15%, Mn10-11%, Si≤0.8%, P≤0.03%, S 0.12-0.15%, Cr 13-14%, Ni 3-4%, Cu 0.3-0.6%, all the other are Fe and inevitable micro impurity element.
2. the method for the described free cutting stainless steel of production claim 1 comprises smelting, cast, blank forging rolling and the heat treated step of blank forging rolling spare, it is characterized in that, in smelting process, comprises following operation:
(1) melting period when electric furnace just refines and oxidation initial stage, the oxidation molten steel fully takes off P, accounts for total steel quality≤0.03% until the content of P; Desiliconization makes the content of silicon account for total steel quality≤0.80%;
(2) reduction period deoxidation, transfer S, the content of S is controlled at accounts within total steel quality 0.12-0.15%;
(3) add alloying element: mainly be by bath analysis, adjust the content of manganese, copper, chromium, nickel, thereby make the mass percent of manganese reach 10-11%, the mass percent of copper reaches 0.3-0.6%, the mass percent of chromium reaches 13-14%, and the mass percent of nickel reaches 3-4%.
(4) when refining furnace is smelted, carry out decarburization, degasification and fine setting alloying element; Just the molten steel after the refining enters the vacuum refinement of VOD stove, and evacuated time is no less than 8 minutes, and vacuum tightness is not more than 1.5mbar, reaches content<30ppm, the content<80ppm of nitrogen, the content<2.5ppm of hydrogen of oxygen.
CN2008102355328A 2008-11-28 2008-11-28 Novel easy-to-cut stainless steel 303B and manufacturing method thereof Expired - Fee Related CN101413091B (en)

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Publication number Priority date Publication date Assignee Title
CN101876034B (en) * 2009-05-01 2013-01-23 衡阳市金则利特种合金有限公司 Lead-free free-cutting austenitic stainless steel
CN105861955B (en) * 2016-05-31 2018-01-19 上海大学兴化特种不锈钢研究院 A kind of economical sulfur-bearing Cutting free austenitic stainless steel alloy material
CN107746908B (en) * 2017-09-19 2019-07-12 舞阳钢铁有限责任公司 A kind of low-phosphorous low silicon Cr-Mo steel ingot smelting process of low-sulfur
CN110669901A (en) * 2019-10-25 2020-01-10 攀钢集团江油长城特殊钢有限公司 Smelting method of sulfur-containing free-cutting stainless steel in electric arc furnace
CN111850407B (en) * 2020-07-29 2021-10-08 成都先进金属材料产业技术研究院有限公司 850 MPa-grade titanium-containing free-cutting stainless steel forged bar and preparation method thereof
CN112063923B (en) * 2020-09-07 2022-03-22 成都先进金属材料产业技术研究院股份有限公司 1300 MPa-grade RE-containing chalcogenide free-cutting steel 60mm bar and preparation method thereof
CN112974738A (en) * 2021-04-23 2021-06-18 北京科技大学 Continuous casting microalloying production method

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CN1050227A (en) * 1990-09-24 1991-03-27 冶金工业部钢铁研究总院 Magnetism-free stainless steel
CN1080330A (en) * 1993-06-08 1994-01-05 天津大学 Austenitic stainless steel
JP2001011573A (en) * 1999-06-25 2001-01-16 Sumitomo Metal Ind Ltd Steel sheet for enameling excellent in fishscale resistance and adhesion and its production

Patent Citations (3)

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Publication number Priority date Publication date Assignee Title
CN1050227A (en) * 1990-09-24 1991-03-27 冶金工业部钢铁研究总院 Magnetism-free stainless steel
CN1080330A (en) * 1993-06-08 1994-01-05 天津大学 Austenitic stainless steel
JP2001011573A (en) * 1999-06-25 2001-01-16 Sumitomo Metal Ind Ltd Steel sheet for enameling excellent in fishscale resistance and adhesion and its production

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