CN113604744A - High-strength and high-toughness cold-work die steel and preparation method thereof - Google Patents
High-strength and high-toughness cold-work die steel and preparation method thereof Download PDFInfo
- Publication number
- CN113604744A CN113604744A CN202110912796.8A CN202110912796A CN113604744A CN 113604744 A CN113604744 A CN 113604744A CN 202110912796 A CN202110912796 A CN 202110912796A CN 113604744 A CN113604744 A CN 113604744A
- Authority
- CN
- China
- Prior art keywords
- furnace
- equal
- steel
- molten steel
- less
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- 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
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/10—Handling in a vacuum
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
-
- 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
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
-
- 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
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- 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
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- 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
- C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
-
- 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
- C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
-
- 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
- C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
-
- 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
- C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
-
- 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
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
-
- 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
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
-
- 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
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
-
- 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
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
The invention provides high-strength and high-toughness cold-work die steel which comprises the following components: 0.9 to 0.94 weight percent of C; 1.35 wt% -1.45 wt% of Si; 0.4 wt% to 0.6 wt% Mn; p is less than or equal to 0.02wt percent; less than or equal to 0.003 weight percent of S; 7.4 to 7.8 weight percent of Cr; 2.1-2.3 wt% of Mo; 0.3 to 0.35 weight percent of V; 0.4 wt% -0.5 wt% of Nb; cu of less than or equal to 0.2 wt%; less than or equal to 0.2 wt% of Ni; 0.02 to 0.03 weight percent of Al; less than or equal to 2.5ppm of H; o is less than or equal to 0.002wt percent; trace amount of rare earth Re; the balance being Fe. The invention provides the high-strength and high-toughness cold-work die steel with specific components and the preparation process, and the cold-work die steel has better structural performance and avoids the unqualified flaw detection problem caused by massive carbides. The invention also provides a preparation method of the high-strength and high-toughness cold-work die steel.
Description
Technical Field
The invention belongs to the technical field of cold-work die steel, and particularly relates to high-strength and high-toughness cold-work die steel and a preparation method thereof.
Background
The usage amount of the cold stamping die is increased year by year, and the cold stamping die becomes important process equipment for producing various plate parts. The metal material used as a cold stamping die is greatly affected by cold extrusion forming and blanking force during use, and particularly important parts such as a male die and a female die are required to have strong strength, toughness and wear resistance. The steel types commonly used for the cold stamping die are Cr12MoV, SKD11 and D2, and the chemical compositions of the three types of steel are basically equivalent.
In order to further improve the toughness of the cold stamping die and maintain the original strength, the Japan Daibid company develops DC53 (the domestic mark is Cr8Mo2SiV) on the basis of Cr12MoV steel, and when designing the chemical components, the proportion of the contents of carbon and chromium is reduced, and further the precipitation of eutectic carbide is reduced to improve the toughness. However, practical production practices show that the steel grades still have the quality problem of flaw detection failure caused by large-block co-carbides.
Disclosure of Invention
In view of the above, the present invention provides a high strength and toughness cold-work die steel and a preparation method thereof, so as to achieve the purpose of reducing or improving eutectic carbides.
The invention provides high-strength and high-toughness cold-work die steel which comprises the following components:
0.9 to 0.94 weight percent of C;
1.35 wt% -1.45 wt% of Si;
0.4 wt% to 0.6 wt% Mn;
p is less than or equal to 0.02wt percent;
less than or equal to 0.003 weight percent of S;
7.4 to 7.8 weight percent of Cr;
2.1-2.3 wt% of Mo;
0.3 to 0.35 weight percent of V;
0.4 wt% -0.5 wt% of Nb;
cu of less than or equal to 0.2 wt%;
less than or equal to 0.2 wt% of Ni;
0.02 to 0.03 weight percent of Al;
less than or equal to 2.5ppm of H;
o is less than or equal to 0.002wt percent;
trace amount of rare earth Re;
the balance being Fe.
The invention provides a preparation method of high-strength and high-toughness cold-work die steel, which comprises the following steps:
sequentially carrying out electric furnace smelting, LF furnace refining and VD vacuum refining on the alloy raw materials to obtain molten steel;
and pouring the molten steel to obtain the high-strength and high-toughness cold-work die steel.
Preferably, the preparation method of the high-strength and high-toughness cold-work die steel comprises the following steps:
taking scrap steel as a raw material, and sequentially carrying out 40t electric furnace smelting, 40t LF furnace refining and 40t VD furnace vacuum refining by adopting a return method to obtain molten steel;
and then casting the molten steel into ingots to obtain the high-strength and high-toughness cold-work die steel slab ingots.
Preferably, the preparation method of the high-strength and high-toughness cold-work die steel comprises the following steps:
taking Cr12MoV, Cr12 and 4Cr13 scrap steel as steelmaking raw materials, and sequentially carrying out 40t electric furnace smelting, 40tLF furnace refining and 40t VD furnace vacuum refining to obtain molten steel with target components;
and casting the molten steel into ingots to obtain the high-strength and high-toughness cold-work die steel flat ingots.
Preferably, the tapping temperature in the electric furnace smelting process is more than or equal to 1600 ℃.
Preferably, the charging temperature of molten steel in the LF furnace refining process is more than or equal to 1510 ℃, and the slag thickness is 31-35 mm;
and firstly feeding an aluminum wire in the LF refining process, wherein the adding amount of the aluminum wire is 120-150 m/furnace molten steel, and simultaneously introducing argon into the furnace bottom, wherein the flow rate is 80-100 NL/min.
Preferably, slag charge lime and refining slag which are prepared in advance are added in the LF furnace refining process, and then lime is added;
the addition amount of the slag charge lime is 500-580 kg/furnace molten steel, the addition amount of the refining slag is 120-140 kg/furnace molten steel, and the addition amount of the supplementary lime is 180-200 kg/furnace molten steel.
Preferably, power transmission reduction is carried out in the LF furnace refining process, and carbon powder and steel slag are added in the power transmission reduction process;
the using amount of the carbon powder is 80-100 kg/furnace molten steel, and the using amount of the steel slag is 100-150 kg/furnace molten steel; the steel slag is added in the following mode: after the power is supplied for refining for 10-15 min, adding 100-150 kg of steel slag friend per furnace molten steel, and adding the steel slag friend for reduction according to 35-40 kg of steel slag per furnace molten steel, 30-35 kg of steel slag per furnace molten steel and 20-30 kg of steel slag per furnace molten steel every 10min in the refining period; after the reduction is completed, the slag is white, a sample is taken for analysis (including total Al), and the total Al is adjusted to 0.05 wt% according to the analysis result.
Preferably, the white slag is kept for 20-25 min in the LF refining process, and 10-15 kg/furnace molten steel carbon powder is supplemented in the later refining stage to keep the reducing atmosphere.
Preferably, in the refining process of the LF furnace, according to a sampling analysis result, chemical components are adjusted according to the related requirements of specific chemical component control, Nb alloying is carried out, and Nb iron is added according to 0.05-0.1% of the weight of molten steel; and (3) controlling the total aluminum after the refining of the LF furnace: [ Al ]: 0.02 to 0.04 wt%.
Preferably, after alloying in the refining process of the LF furnace is finished, sampling and full analysis are carried out, and VD furnace operation is carried out when chemical components enter an internal control range, S is less than or equal to 0.003 wt%, and the temperature is 1610-1640 ℃.
Preferably, the temperature of the ladle in the VD vacuum refining process is 1610-1640 ℃;
the thickness of the slag is less than or equal to 80mm when the slag is added into VD.
Preferably, the ultimate vacuum degree in the VD vacuum refining process is less than or equal to 60Pa, and the holding time under the ultimate vacuum is more than or equal to 20 min.
Preferably, in the VD vacuum refining process, the large flow of Ar blowing is kept under the limit vacuum, and the flow of Ar blowing is more than or equal to 130 NL/min; adjusting the flow rate of blowing Ar to 20-40 NL/min 1-2 min before air break.
Preferably, the VD vacuum material dividing process includes:
breaking the hollow, measuring the temperature, and taking an [ H ] sample, wherein the [ H ] is required to be less than or equal to 2.5 ppm;
after the VD vacuum furnace is emptied, adding 13-17 kg of rare earth Re/furnace molten steel immediately, putting the rare earth Re into an aluminum lunch box, and directly throwing into a steel ladle;
after the rare earth is added, the ladle can be used for pouring after the soft argon blowing time is more than or equal to 25min, and if the soft argon blowing time exceeds 50min, the operation of determining [ H ] needs to be carried out again.
Preferably, the temperature of the ladle in the casting process is 1505-1515 ℃, and finally, the ingot is cast.
The invention provides the high-strength and high-toughness cold-work die steel with specific components and the preparation process, which can reduce or improve the problem of eutectic carbide, has better structure performance, and avoids the unqualified flaw detection problem caused by massive carbide.
Drawings
FIG. 1 is a metallographic picture of eutectic carbide at the edge of a flat steel prepared in example 1 of the present invention;
FIG. 2 is a metallographic picture of eutectic carbide at the center of a flat steel prepared in example 1 of the present invention;
FIG. 3 is a metallographic picture of eutectic carbide at the edge of a flat steel prepared in example 2 of the present invention;
FIG. 4 is a metallographic picture of eutectic carbide at the center of the flat steel prepared in example 2 of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other examples, which may be modified or appreciated by those of ordinary skill in the art based on the examples given herein, are intended to be within the scope of the present invention. It should be understood that the embodiments of the present invention are only for illustrating the technical effects of the present invention, and are not intended to limit the scope of the present invention. In the examples, the methods used were all conventional methods unless otherwise specified.
The invention provides high-strength and high-toughness cold-work die steel which comprises the following components:
0.90 to 0.94 weight percent of C;
1.35 wt% -1.45 wt% of Si;
0.4 wt% to 0.6 wt% Mn;
p is less than or equal to 0.02wt percent;
less than or equal to 0.003 weight percent of S;
7.4 to 7.8 weight percent of Cr;
2.1-2.3 wt% of Mo;
0.3 to 0.35 weight percent of V;
0.4 wt% -0.5 wt% of Nb;
cu of less than or equal to 0.2 wt%;
less than or equal to 0.2 wt% of Ni;
0.02 to 0.03 weight percent of Al;
less than or equal to 2.5ppm of H;
o is less than or equal to 0.002wt percent;
trace amount of rare earth Re;
the balance being Fe.
In the invention, the mass content of C is preferably 0.91-0.93%, more preferably 0.92%; the mass content of the Si is preferably 1.38-1.42%, and most preferably 1.4%; the mass content of Mn is preferably 0.5%; the mass content of P is preferably less than or equal to 0.02 wt%; the mass content of S is preferably less than or equal to 0.003 wt%; the mass content of Cr is preferably 7.5-7.7%, and more preferably 7.6%; the mass content of Mo is preferably 2.2%; the mass content of V is preferably 0.31-0.34%, more preferably 0.32-0.33%; the mass content of Nb is preferably 0.45%; the mass content of Cu is preferably less than or equal to 0.2 wt%; the mass content of the Ni is preferably less than or equal to 0.2 wt%; the mass content of the Al is preferably 0.025%; the mass content of H is preferably less than or equal to 2.5 ppm; the mass content of O is preferably less than or equal to 0.002 wt%.
The invention provides a preparation method of high-strength and high-toughness cold-work die steel, which comprises the following steps:
sequentially carrying out electric furnace smelting, LF furnace refining and VD vacuum refining on the alloy raw materials to obtain molten steel with qualified components;
and pouring the molten steel to obtain the high-strength and high-toughness cold-work die steel ingot.
In the invention, the preparation method of the high-strength and high-toughness cold-work die steel comprises the following steps:
taking scrap steel as a raw material, and sequentially carrying out 40t electric furnace smelting, 40t LF furnace refining and 40t VD furnace vacuum refining by adopting a return method to obtain molten steel;
and then casting the molten steel into ingots to obtain the high-strength and high-toughness cold-work die steel slab ingots.
In the present invention, the method for preparing the high-toughness cold-work die steel more preferably comprises:
taking Cr12MoV, Cr12 and 4Cr13 scrap steel as steelmaking raw materials, and sequentially carrying out 40t electric furnace smelting, 40tLF furnace refining and 40t VD furnace vacuum refining to obtain molten steel with qualified components;
and casting the molten steel into ingots to obtain the high-strength and high-toughness cold-work die steel flat ingots.
In the present invention, the electric furnace is preferably a 40t electric furnace; the LF furnace is preferably a 40t LF furnace; the VD vacuum refining furnace is preferably a 40t vacuum refining furnace.
The alloy raw materials are not particularly limited in the invention, and the alloy raw materials for preparing cold-work die steel well known to those skilled in the art can be used for batching, preferably waste steel, and more preferably one or more of Cr12MoV waste steel, Cr12 waste steel and 4Cr13 waste steel. In the invention, the components of the alloy raw materials are consistent with those of the high-strength and high-toughness cold-work die steel in the technical scheme.
In the invention, the electric furnace smelting process preferably adopts a reduction method for smelting; the tapping temperature in the electric furnace smelting process is preferably not less than 1600 ℃, more preferably 1610 to 1630 ℃, and most preferably 1620 ℃.
In the invention, the charging condition of the molten steel in the refining process of the LF furnace is preferably that the temperature is more than or equal to 1510 ℃, more preferably 1520-1540 ℃, and most preferably 1530 ℃; the slag thickness is preferably 31-35 mm, more preferably 32-34 mm, and most preferably 33 mm.
In the invention, an aluminum wire is preferably fed in the LF furnace refining process, and the adding amount of the aluminum wire is preferably 130-140 m/furnace molten steel, more preferably 132-138 m/furnace molten steel, and most preferably 134-136 m/furnace molten steel.
In the invention, during the refining process of the LF furnace, argon is preferably introduced into the furnace bottom while feeding an aluminum wire; the flow rate of the argon gas is preferably 80-100 NL/min, more preferably 85-95 NL/min, and most preferably 90 NL/min.
In the invention, lime and refining slag are preferably added in the refining process of the LF furnace, and then lime is supplemented; the addition amount of the lime is preferably 510-580 kg/furnace molten steel, more preferably 520-560 kg/furnace molten steel, more preferably 530-550 kg/furnace molten steel, and most preferably 540 kg/furnace molten steel.
In the invention, the addition amount of the refining slag is preferably 125-140 kg/furnace molten steel, more preferably 130-135 kg/furnace molten steel, and most preferably 132-133 kg/furnace molten steel.
In the invention, the addition amount of the supplementary lime is preferably 185-200 kg/furnace molten steel, more preferably 190-195 kg/furnace molten steel, and most preferably 192-193 kg/furnace molten steel.
In the invention, the LF furnace is preferably subjected to power transmission reduction in the refining process, carbon powder and steel slag are adopted for reduction in the power transmission reduction process, the use amount of the carbon powder is preferably 85-100 kg/furnace molten steel, more preferably 90-95 kg/furnace molten steel, and most preferably 92-93 kg/furnace molten steel.
In the invention, the dosage of the steel slag is preferably 100-150 kg/furnace molten steel, more preferably 110-140 kg/furnace molten steel, and most preferably 120-130 kg/furnace molten steel.
In the present invention, the method for adding the steel slag preferably comprises:
after the refining is carried out for 10-15 min, 100-150 kg of steel slag is added per furnace of molten steel, preferably 110-140 kg of steel slag per furnace of molten steel, and most preferably 120-130 kg of steel slag per furnace of molten steel.
In the invention, the steel slag friend is preferably added in a refining period in a segmented manner, and the steel slag friend is added for reduction according to 35-40 kg/furnace molten steel, 30-35 kg/furnace molten steel and 20-30 kg/furnace molten steel every 10 min.
In the invention, in the LF furnace refining process, preferably, after complete reduction and white slag, sampling analysis (including all Al) is carried out, the sample is returned, the all Al in the molten steel is adjusted to 0.05 wt% according to the analysis result, the retention time of the white slag is preferably 20-25 min, more preferably 21-24 min, and most preferably 22-23 min; adding carbon powder in the later stage of refining to keep a reducing atmosphere; the adding amount of the carbon powder is preferably 10-15 kg/furnace molten steel, more preferably 11-14 kg/furnace molten steel, and most preferably 12-13 kg/furnace molten steel.
In the invention, in the refining process of the LF furnace, the chemical composition is preferably adjusted according to the requirements related to chemical composition control of specific steel types, Nb is alloyed, and Nb iron is added according to 0.05-0.1% of the weight of molten steel, more preferably 0.06-0.09%, and most preferably 0.07-0.08%.
In the invention, the content of total aluminum in the molten steel after LF refining is preferably 0.02-0.04 wt%, and more preferably 0.03 wt%; preferably, the mass content of S in the molten steel is less than or equal to 0.003 percent, and the molten steel is subjected to ladle deslagging at the temperature of 1610-1640 ℃, and then subjected to VD vacuum refining.
In the invention, the VD slag thickness is preferably less than or equal to 80mm, more preferably 70-80 mm, and most preferably 75mm in the VD vacuum refining process.
In the invention, the ultimate vacuum degree in the VD vacuum refining process is preferably less than or equal to 60Pa, more preferably 50-60 Pa, and most preferably 55 Pa; the time for keeping under the ultimate vacuum is preferably not less than 20min, more preferably 20-25 min, and most preferably 22-23 min.
In the invention, in the VD vacuum refining process, the large flow of Ar blowing is preferably kept under the ultimate vacuum, and the flow of Ar blowing is preferably not less than 130NL/min, more preferably 130-150 NL/min, and most preferably 140 NL/min; preferably, the flow rate of Ar blowing is adjusted to 20 to 40NL/min, more preferably 25 to 35NL/min, and most preferably 30NL/min before the air break for 1 to 2 min.
In the invention, the VD vacuum refining process is preferably carried out with the steps of breaking empty, measuring temperature and taking an [ H ] sample, and the [ H ] content in the molten steel is preferably controlled to be less than or equal to 2.5 ppm.
In the VD vacuum refining process, preferably after the VD vacuum furnace is broken empty, the rare earth Re 13-17 kg/furnace molten steel is added immediately, more preferably 14-16 kg/furnace molten steel, and most preferably 15 kg/furnace molten steel.
In the present invention, the method of adding the rare earth preferably includes:
the rare earth Re is put into an aluminum lunch box and then directly thrown into a ladle.
In the invention, after the rare earth is added, the rare earth can be poured by a ladle after the soft argon blowing time is preferably more than or equal to 25min, and if the soft argon blowing time exceeds 50min, the operation of determining [ H ] needs to be carried out again.
In the invention, the temperature of the ladle in the pouring process is preferably 1505-1515 ℃, more preferably 1508-1512 ℃, and most preferably 1510 ℃.
The invention provides the high-strength and high-toughness cold-work die steel with specific components and the preparation process, which can reduce or improve the problem of eutectic carbide, has better structure performance, and avoids the unqualified flaw detection problem caused by massive carbide.
Example 1
Taking Cr12MoV, Cr12 and 4Cr13 scrap steel as steelmaking raw materials, and sequentially carrying out 40t electric furnace smelting, 40t LF furnace refining and 40t VD vacuum refining to obtain molten steel with qualified chemical components;
pouring the molten steel to obtain a high-strength high-toughness cold-work die steel slab ingot;
the electric furnace smelting process comprises the following steps: smelting by adopting a reduction method according to a conventional smelting process, wherein the tapping temperature is 1620 ℃;
in the LF furnace refining process: the temperature of molten steel after entering the LF furnace is 1550 ℃, and the slag thickness is 35 mm;
feeding an aluminum wire 150m, adjusting the argon flow to 90NL/min, adding 570kg of slag charge lime and 120kg of refining slag which are prepared in advance, and supplementing 200kg of lime;
and (3) power transmission reduction, wherein carbon powder with the total amount of 100kg and steel slag with the total amount of 100kg are used in the whole process for reduction, and the steel slag is added in a mode that: feeding 100kg of steel slag after refining for 15min, and feeding 40kg, 30kg and 30kg of steel slag for reduction at intervals of 10min in the refining period;
reducing completely, white slag, sampling and analyzing (including all Al), returning a sample, and adjusting the total Al to 0.05 wt% according to an analysis result; the white slag is kept for 24min in the refining process, and a small amount of C powder (10 kg/furnace molten steel) is added in the later stage of refining to keep the reducing atmosphere;
according to the sampling analysis result, adjusting chemical components according to the related requirements of controlling the chemical components of specific steel grades, and adding Nb iron according to 0.06 percent of the total weight of the molten steel; after the refining of the LF furnace is finished, the total aluminum [ Al ]: 0.04 wt%;
ensuring good alloying, sampling and analyzing completely, when chemical components enter internal control, the S content is less than or equal to 0.003 wt%, the temperature is 1640 ℃, hoisting a ladle for deslagging, and then hoisting the ladle to VD for vacuum treatment;
in the VD vacuum refining process: the thickness of the VD slag is 70 mm;
the vacuum treatment requirement of the VD furnace is as follows: the ultimate vacuum degree is 50Pa, and the holding time under the ultimate vacuum is 25 min;
keeping large flow Ar blowing (blowing Ar flow 140NL/min) under ultimate vacuum, and adjusting the blowing Ar flow to 40NL/min 2min before breaking;
breaking the cavity, measuring the temperature, and taking an [ H ] sample, wherein the [ H ] is 2.5 ppm;
after the VD vacuum furnace is emptied, adding the rare earth Re15 kg/furnace molten steel immediately, putting the rare earth Re into an aluminum lunch box, and then directly throwing into a steel ladle; after the rare earth is added, the ladle can be used for pouring after the soft argon blowing time is 28min, and if the soft argon blowing time exceeds 50min, the operation of determining [ H ] needs to be carried out again;
the ladle temperature during the pouring process is 1514 ℃.
According to the method for measuring the contents of multiple elements in carbon steel and medium-low alloy steel in GB/T4336-2016 (conventional method for measuring the contents of elements in carbon steel and medium-low alloy steel), the components of the high-strength high-toughness cold-work die steel prepared in the embodiment 1 of the invention are detected, and the detection results are shown in Table 1:
table 1 detection results of the components of the high strength and high toughness cold work die steel prepared in example 1 of the present invention
After rolling the slab ingot prepared in the embodiment 1 of the present invention into a flat steel with a thickness of 70mm, sampling and analyzing the metallographic structure of the edge and the center of the cross section, as shown in fig. 1 and 2, fig. 1 is the metallographic structure of the edge, and fig. 2 is the metallographic structure of the center; the grade of the unevenness of the eutectic carbide was 0.5 in accordance with GB/T14979-1994 method for the unevenness of the eutectic carbide of steel.
Example 2
Taking Cr12MoV, Cr12 and 4Cr13 scrap steel as steelmaking raw materials, and sequentially carrying out 40t electric furnace smelting, 40t LF furnace refining and 40t VD vacuum refining to obtain molten steel with qualified chemical components;
pouring the molten steel to obtain a high-strength high-toughness cold-work die steel slab ingot;
the electric furnace smelting process comprises the following steps: smelting by adopting a reduction method according to a conventional smelting process, wherein the tapping temperature is 1610 ℃;
in the LF furnace refining process: after the molten steel is put into an LF furnace, the temperature is 1560 ℃, and the slag thickness is 31 mm;
feeding an aluminum wire 150m, adjusting the flow rate of argon (95NL/min), adding 510kg of slag charge lime and 140kg of refining slag which are prepared in advance, and supplementing 180kg of lime;
carrying out power transmission reduction, wherein carbon powder with the total amount of 80kg and steel slag with the total amount of 130kg are used in the whole process; the steel slag is added in the following mode: charging 130kg of steel slag friend after refining for 12min by power transmission, and charging 50kg, 40kg and 40kg of steel slag friend every 10min during refining for reduction;
reducing completely, white slag, sampling and analyzing (including all Al), returning a sample, and adjusting the total Al to 0.05 wt% according to an analysis result; the white slag is kept for 21min in the refining process, and a small amount of C powder (10 kg/furnace molten steel) is added in the later stage of refining to keep the reducing atmosphere.
According to the sampling analysis result, adjusting chemical components according to the related requirements of controlling the chemical components of specific steel grades, and adding Nb iron according to 0.1 percent of the total weight of the molten steel; after the refining of the LF furnace is finished, the total aluminum [ Al ]: 0.03 wt%;
ensuring good alloying, sampling and fully analyzing; when the chemical components enter the internal control, the S content is less than or equal to 0.003wt percent and the temperature is 1615 ℃; after deslagging, hoisting the ladle to VD for vacuum treatment;
in the VD vacuum refining process: the thickness of the VD slag is 72 mm;
the vacuum treatment requirement of the VD furnace is as follows: the ultimate vacuum degree is 55Pa, and the holding time under the ultimate vacuum is 21 min;
keeping large flow Ar blowing (blowing Ar flow rate is 130NL/min) under ultimate vacuum, and adjusting the blowing Ar flow rate to 50NL/min 2min before breaking;
breaking the cavity, measuring the temperature, and taking an [ H ] sample, wherein the [ H ] is 2 ppm;
after the VD vacuum furnace is emptied, adding the rare earth Re15 kg/furnace molten steel immediately, putting the rare earth Re into an aluminum lunch box, and then directly throwing into a steel ladle; after the rare earth is added, the ladle can be used for pouring after the soft argon blowing time is 25min, and if the soft argon blowing time exceeds 50min, the operation of determining [ H ] needs to be carried out again;
the ladle temperature in the pouring process is 1506 ℃.
The components of the high-strength high-toughness cold-work die steel prepared in example 2 of the invention were measured according to the method of example 1, and the measurement results are shown in table 2:
table 2 detection results of components of high-strength and high-toughness cold-work die steel prepared in example 2 of the present invention
| C | Si | Mn | P | S | Cr | Mo | Balance of |
| 0.91wt％ | 1.36wt％ | 0.41wt％ | 0.02wt％ | 0.003wt％ | 7.45wt％ | 2.15wt％ | Fe |
| V | Nb | Cu | Ni | Al | H | O | |
| 0.32wt％ | 0.4wt％ | 0.15wt％ | 0.15wt％ | 0.025wt％ | 2ppm | 0.002 |
After the slab prepared in example 2 of the present invention was rolled into a slab having a thickness of 70mm, the edge and the center of the cross section were subjected to metallographic analysis by sampling, and as shown in fig. 3 and 4, the unevenness of eutectic carbide was rated according to the method of example 1, and the results were all 1.0 grade.
The invention provides the high-strength and high-toughness cold-work die steel with specific components and the preparation process, which can reduce or improve the problem of eutectic carbide, has better structure performance, and avoids the unqualified flaw detection problem caused by massive carbide.
While only the preferred embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
Claims (10)
1. A high-strength and high-toughness cold-work die steel comprises the following components:
0.9 to 0.94 weight percent of C;
1.35 wt% -1.45 wt% of Si;
0.4 wt% to 0.6 wt% Mn;
p is less than or equal to 0.02wt percent;
less than or equal to 0.003 weight percent of S;
7.4 to 7.8 weight percent of Cr;
2.1-2.3 wt% of Mo;
0.3 to 0.35 weight percent of V;
0.4 wt% -0.5 wt% of Nb;
cu of less than or equal to 0.2 wt%;
less than or equal to 0.2 wt% of Ni;
0.02 to 0.03 weight percent of Al;
less than or equal to 2.5ppm of H;
o is less than or equal to 0.002wt percent;
trace amount of rare earth Re;
the balance being Fe.
2. A method for preparing the high-toughness cold-work die steel as claimed in claim 1, which comprises the following steps:
sequentially carrying out electric furnace smelting, LF furnace refining and VD vacuum refining on the alloy raw materials to obtain molten steel;
and pouring the molten steel to obtain the high-strength and high-toughness cold-work die steel.
3. The method according to claim 2, characterized in that the tapping temperature during the electric furnace smelting is more than or equal to 1600 ℃.
4. The method according to claim 2, wherein the charging temperature of molten steel in the LF furnace refining process is not less than 1510 ℃, and the slag thickness is 31-35 mm;
and feeding an aluminum wire in the LF refining process, wherein the adding amount of the aluminum wire is 120-150 m/furnace molten steel.
5. The method of claim 2, wherein slag lime and refining slag are added in the LF furnace refining process, and then lime is added;
the addition amount of lime is 500-580 kg/furnace molten steel, the addition amount of refining slag is 120-140 kg/furnace molten steel, and the addition amount of supplementary lime is 180-200 kg/furnace molten steel.
6. The method as claimed in claim 2, wherein the LF furnace is subjected to power transmission reduction in the refining process, and carbon powder and steel slag are adopted in the power transmission reduction process;
the using amount of the carbon powder is 80-100 kg/furnace molten steel, and the using amount of the steel slag is 100-150 kg/furnace molten steel.
7. The method according to claim 2, wherein the temperature of the ladle in the VD vacuum refining process is 1610-1640 ℃;
the thickness of the slag is less than or equal to 80mm when the slag is added into VD.
8. The method according to claim 2, wherein the ultimate vacuum degree in the VD vacuum refining process is less than or equal to 60Pa, and the holding time under the ultimate vacuum is more than or equal to 20 min.
9. The method according to claim 2, wherein in the VD vacuum refining process, Ar blowing is kept at a large flow rate under the limit vacuum, and the flow rate of Ar blowing is more than or equal to 130 NL/min; adjusting the flow rate of blowing Ar to 20-40 NL/min 1-2 min before air break.
10. The method according to claim 2, wherein the ladle temperature during the pouring process is 1505-1515 ℃.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110912796.8A CN113604744B (en) | 2021-08-10 | 2021-08-10 | High-strength and high-toughness cold-work die steel and preparation method thereof |
| AU2022325314A AU2022325314A1 (en) | 2021-08-10 | 2022-07-20 | High-toughness, cold-worked die steel and preparation method therefor |
| KR1020237019602A KR20230104949A (en) | 2021-08-10 | 2022-07-20 | High-strength and high-toughness cold-worked mold steel and manufacturing method thereof |
| PCT/CN2022/106861 WO2023016219A1 (en) | 2021-08-10 | 2022-07-20 | High-toughness, cold-worked die steel and preparation method therefor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110912796.8A CN113604744B (en) | 2021-08-10 | 2021-08-10 | High-strength and high-toughness cold-work die steel and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113604744A true CN113604744A (en) | 2021-11-05 |
| CN113604744B CN113604744B (en) | 2022-12-27 |
Family
ID=78307924
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110912796.8A Active CN113604744B (en) | 2021-08-10 | 2021-08-10 | High-strength and high-toughness cold-work die steel and preparation method thereof |
Country Status (4)
| Country | Link |
|---|---|
| KR (1) | KR20230104949A (en) |
| CN (1) | CN113604744B (en) |
| AU (1) | AU2022325314A1 (en) |
| WO (1) | WO2023016219A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023016219A1 (en) * | 2021-08-10 | 2023-02-16 | 攀钢集团攀枝花钢铁研究院有限公司 | High-toughness, cold-worked die steel and preparation method therefor |
| CN115747671A (en) * | 2022-11-18 | 2023-03-07 | 攀钢集团江油长城特殊钢有限公司 | Preparation method of cold-work die steel |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1295625A (en) * | 1998-03-27 | 2001-05-16 | 尤迪霍尔姆工具公司 | Cold work steel |
| JP2002012952A (en) * | 2000-06-29 | 2002-01-15 | Sanyo Special Steel Co Ltd | Tool steel for cold working |
| JP2009235562A (en) * | 2008-03-05 | 2009-10-15 | Sanyo Special Steel Co Ltd | Steel for cold press die excellent in machinability, heat treatment dimensional change characteristic and impact characteristic, and press die |
| CN103014495A (en) * | 2012-12-01 | 2013-04-03 | 滁州市成业机械制造有限公司 | High-tenacity high-wear-resistance cold-work die steel and processing method thereof |
| CN103290328A (en) * | 2013-05-30 | 2013-09-11 | 钢铁研究总院 | High-niobium, high-wear-resistance and high-toughness cold-work die steel |
| JP2014031575A (en) * | 2012-07-09 | 2014-02-20 | Hitachi Metals Ltd | Steel for high hardness cold die and manufacturing method thereof |
| CN105637108A (en) * | 2014-09-26 | 2016-06-01 | 日立金属株式会社 | Cold tool material and method for manufacturing cold tool |
| CN111518987A (en) * | 2020-04-28 | 2020-08-11 | 成都先进金属材料产业技术研究院有限公司 | Rare earth adding method for Cr12 cold work die steel refining |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0711056B2 (en) * | 1985-05-30 | 1995-02-08 | 大同特殊鋼株式会社 | Die steel manufacturing method |
| JP2002012950A (en) * | 2000-06-28 | 2002-01-15 | Nippon Steel Corp | 9% Ni STEEL WITH HIGH TOUGHNESS |
| CN113604744B (en) * | 2021-08-10 | 2022-12-27 | 攀钢集团攀枝花钢铁研究院有限公司 | High-strength and high-toughness cold-work die steel and preparation method thereof |
-
2021
- 2021-08-10 CN CN202110912796.8A patent/CN113604744B/en active Active
-
2022
- 2022-07-20 KR KR1020237019602A patent/KR20230104949A/en unknown
- 2022-07-20 WO PCT/CN2022/106861 patent/WO2023016219A1/en unknown
- 2022-07-20 AU AU2022325314A patent/AU2022325314A1/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1295625A (en) * | 1998-03-27 | 2001-05-16 | 尤迪霍尔姆工具公司 | Cold work steel |
| JP2002012952A (en) * | 2000-06-29 | 2002-01-15 | Sanyo Special Steel Co Ltd | Tool steel for cold working |
| JP2009235562A (en) * | 2008-03-05 | 2009-10-15 | Sanyo Special Steel Co Ltd | Steel for cold press die excellent in machinability, heat treatment dimensional change characteristic and impact characteristic, and press die |
| JP2014031575A (en) * | 2012-07-09 | 2014-02-20 | Hitachi Metals Ltd | Steel for high hardness cold die and manufacturing method thereof |
| CN103014495A (en) * | 2012-12-01 | 2013-04-03 | 滁州市成业机械制造有限公司 | High-tenacity high-wear-resistance cold-work die steel and processing method thereof |
| CN103290328A (en) * | 2013-05-30 | 2013-09-11 | 钢铁研究总院 | High-niobium, high-wear-resistance and high-toughness cold-work die steel |
| CN105637108A (en) * | 2014-09-26 | 2016-06-01 | 日立金属株式会社 | Cold tool material and method for manufacturing cold tool |
| CN111518987A (en) * | 2020-04-28 | 2020-08-11 | 成都先进金属材料产业技术研究院有限公司 | Rare earth adding method for Cr12 cold work die steel refining |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023016219A1 (en) * | 2021-08-10 | 2023-02-16 | 攀钢集团攀枝花钢铁研究院有限公司 | High-toughness, cold-worked die steel and preparation method therefor |
| CN115747671A (en) * | 2022-11-18 | 2023-03-07 | 攀钢集团江油长城特殊钢有限公司 | Preparation method of cold-work die steel |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2023016219A1 (en) | 2023-02-16 |
| AU2022325314A1 (en) | 2023-06-29 |
| CN113604744B (en) | 2022-12-27 |
| KR20230104949A (en) | 2023-07-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104894476B (en) | A kind of building grid steel wire rod and preparation method thereof | |
| CN103320704B (en) | High performance bearing steel and production method thereof | |
| WO2023016219A1 (en) | High-toughness, cold-worked die steel and preparation method therefor | |
| CN111187973B (en) | High-elongation RuT400 vermicular graphite cast iron and production process thereof | |
| CN102268608B (en) | Large capacity high pressure gas cylinder steel and production method thereof | |
| CN110656277A (en) | Heat-resistant steel for automobile turbine shell and exhaust pipe and preparation method thereof | |
| CN100463994C (en) | Nb-Ti microalloying steel suitable for large line energy welding and smelting method therefor | |
| CN113046627B (en) | 345 MPa-grade weather-proof bridge steel and manufacturing method thereof | |
| CN113355601B (en) | Low-cost high-corrosion-resistant steel bar and production method thereof | |
| CN109402498A (en) | A kind of high-temperature carburizing pinion steel and its manufacturing method | |
| CN110343949A (en) | HRB400E high-strength anti-seismic steel bar production method and steel containing niobium vanadium | |
| CN113145807A (en) | Rare earth bearing steel ingot for shield machine and production method thereof | |
| CN109536664B (en) | Vermicular graphite cast iron vortex plate and production process thereof | |
| CN110423937B (en) | Alloyed gray cast iron resisting corrosion of high-temperature aluminum and zinc liquid and smelting process thereof | |
| CN109266965A (en) | A kind of hot rolled strip and its preparation and application | |
| CN110172638A (en) | A kind of high-temperature carburizing pinion steel and production method | |
| CN113881888B (en) | Production process of high-strength delayed fracture-resistant cold forging steel | |
| CN110218954A (en) | A kind of preparation method of 4Cr13V plastic die steel | |
| CN108588545A (en) | A kind of GGG70L spheroidal graphite cast-iron and preparation method thereof | |
| CN110669999B (en) | Super-large-section ledeburite cold-work die steel bar and preparation method thereof | |
| CN109797337A (en) | Nonmagnetic steel ingot and its manufacturing method for pump head body | |
| CN113122678B (en) | Smelting method for increasing vanadium and making steel by using vanadium slag | |
| CN115323288B (en) | Preparation method of chalcogenide free-cutting hot-work die steel CX2344 | |
| CN114015924B (en) | Preparation method of continuous casting and rolling H13 series hot work die steel | |
| CN108411186A (en) | A kind of supercritical generating sets C12A steel smelting and pouring techniques |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20230919 Address after: 617000 Taoyuan street, East District, Panzhihua, Sichuan Province, No. 90 Patentee after: PANGANG GROUP PANZHIHUA IRON & STEEL RESEARCH INSTITUTE Co.,Ltd. Patentee after: Chengdu advanced metal material industry technology Research Institute Co.,Ltd. Address before: 617000 Taoyuan street, East District, Panzhihua, Sichuan Province, No. 90 Patentee before: PANGANG GROUP PANZHIHUA IRON & STEEL RESEARCH INSTITUTE Co.,Ltd. |
|
| TR01 | Transfer of patent right |