KR101169654B1 - Forged steel ball having surface of martensite and inner core of bainite for grinding mill - Google Patents
Forged steel ball having surface of martensite and inner core of bainite for grinding mill Download PDFInfo
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- KR101169654B1 KR101169654B1 KR1020120010672A KR20120010672A KR101169654B1 KR 101169654 B1 KR101169654 B1 KR 101169654B1 KR 1020120010672 A KR1020120010672 A KR 1020120010672A KR 20120010672 A KR20120010672 A KR 20120010672A KR 101169654 B1 KR101169654 B1 KR 101169654B1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous alloys
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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
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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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
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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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
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
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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
- C22C38/40—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
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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
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
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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
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
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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
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/002—Bainite
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/008—Martensite
Abstract
Description
The present invention relates to a forged steel ball for use in a ball mill for milling raw materials or products or a tube mill for milling raw ore in a mine. (Rockwell) relates to forged steel balls manufactured to hardness HRC 2-4.
In general, for the manufacture of forged steel balls of grinding ball mills for grinding raw materials or raw ore in cement manufacturers or mining industry, SxxC-based high carbon steels (weight: C: 0.42 ~ 0.48%, Si: 0.15 ~ 0.35) %, Mn: 0.53 ~ 0.90% P: 0.03% or less, S: 0.035% or less Ni: 0.06% ~ 0.20) as a raw material and manufactured by hot forging method (HOT FORGING METHOD) It was.
However, the manufactured forged steel ball (FORGED STEEL BALL), as shown in Figure 1a and 1b the surface is formed of martensite structure, the core portion is a pearlite structure, the hardness difference between the 90mm reference center and the outside was inevitably exist HRC20 ~ 25 . Figure 1a is a 100x picture and Figure 1b is a 500x picture.
When the forged steel ball is put into the mill and operated for 700 hours or more, the wear rate of the steel for about 10 mm is exposed from the surface of the forged steel ball and the pearlite structure is exposed to the steel ball.
In order to overcome this problem, the high chrome casting ball of the method of casting (Method of Casting) has been generalized because the hardness difference between the center and the outside can maintain HRC2 ~ 4 based on 90mm.
However, nonferrous metals such as chromium, which are used raw materials, are more expensive than forged steel balls (SxxC), and most of all, the chromium content harmful to the environment is 15-17% based on 90mm, which contains 6.4g of chromium per ton of cement and the heat inside the mill. As a result of this change, the break rate was greatly increased.
The problem of the present invention for solving the above-described conventional problems, the present invention is to solve the forged steel ball 90mm reference center and the external hardness difference HRC20 ~ 25, which is a problem of the conventional forging technology, While the content is significantly reduced from 15% to 17% to 0.25% to 1.0%, the internal and external hardness differences, which are advantages of high chrome casting balls, reach within HRC2 to 4, and extreme thermal changes The purpose is to manufacture environmentally friendly, wear-resistant steel ball (mill ball) that combines the advantages of forged steel ball that can maintain a low fracture rate (破 球 率).
Forging steel ball used in the grinding mill (Mill) having the surface of the martensite structure and the deep part of the bainite structure according to the present invention for solving the above-described problems, the grinding (Tube Mill) or ball mill (Forged Steel Ball) used in (Ball Mill), the diameter of the forged steel ball is 25 ~ 35mm, the forged steel ball is C: 0.40 ~ 0.65 wt%, Mn: 0.40 ~ 0.85 wt%, Si: 0.15 0.35% by weight, Cr: 0.25% to 1.00% by weight, S: 0.050% by weight or less, P: 0.050% by weight or less, Ni: 0.015% to 0.025% by weight, Mo: 0.009% by weight or less, Cu: 0.010% to 0.050% by weight, W: 0.005% by weight or less, V: 0.005% by weight or less, Ti: 0.005% by weight or less, B: 0.005% by weight or less, and other unavoidable impurities, 0.96-0.98% by weight, and the remaining Fe, and the forged steel balls 1,150-1,200 HOT FREE TYPE FORGING METHOD before heating to 950 ℃, and after forging, isothermal heat treatment at 25 ~ 35 ℃ for 13-30 seconds. After immersing the forged steel ball in a cooling water of 35 ± 5 ° C. for about 45 seconds at a temperature of 780 ± 10 ° C. and undergoing a heat treatment step of naturally cooling at room temperature, the surface is composed of martensite structure and the deep bainite structure. It is characterized by reducing the internal and external hardness difference to within HRC2 ~ 4.
In addition, the forged steel ball used in the grinding mill (Mill) having the surface of the martensite structure and the deep part of the bainite structure according to the present invention, is used in the grinding (Tube Mill) or ball mill (Ball Mill) As forged steel ball (Forged Steel Ball), the diameter of the forged steel ball is 36 ~ 65mm, the forged steel ball is C: 0.40 ~ 0.85 wt%, Mn: 0.60 ~ 1.10 wt%, Si: 0.00 ~ 1.80 wt%, Cr : 0.28 ~ 0.60% by weight, S: 0.040% by weight or less, P: 0.040% by weight or less, Ni: 0.015 ~ 0.025% by weight, Mo: 0.00 ~ 0.009% by weight, Cu: 0.010 ~ 0.050% by weight, W: 0.00 ~ 0.005 Wt%, V: 0.00 ~ 0.005% by weight, Ti: 0.00 ~ 0.005% by weight, B: 0.00 ~ 0.005% by weight, 0.96-0.98% by weight of other unavoidable impurities and the remaining Fe, and the forged steel ball is 1,150-1,200 ° C. After heating to hot free type forging (HOT FREE TYPE FORGING METHOD) before cooling to 950 ℃, the heat treatment method according to the diameter in detail is as follows.
Forging steel ball diameter 36 ~ 45mm is subjected to isothermal heat treatment at 25 ~ 35 ℃ for 30 seconds after forging, and then infiltrated into 35 ± 5 ℃ cooling water at 780 ± 10 ℃ for about 48 seconds at room temperature. Again, a natural heat treatment process.
Forging steel ball diameter 46 ~ 55mm is subjected to isothermal heat treatment at 25 ~ 35 ℃ for 27 seconds after forging, and then immersed in 35 ± 5 ℃ cooling water at 780 ± 10 ℃ for 50 seconds, and then at room temperature. Again, a natural heat treatment process.
The diameter of 56-65mm of the forged steel ball is subjected to an isothermal heat treatment at 25-35 ° C. for 25 seconds after forging, and then immersed in the cooling water of 35 ± 5 ° C. at 780 ± 10 ° C. for about 50-55 seconds. It undergoes a heat treatment process to naturally cool again at room temperature.
In addition, the diameter of the forged steel used in the grinding mill (Mill) having the surface of the martensite structure and the deep part of the bainite structure according to the present invention is 66 ~ 120mm, the forged steel ball is C: 0.72 ~ 0.82% by weight, Mn : 0.70 to 1.10 wt%, Si: 0.17 to 0.37 wt%, Cr: 0.28 to 0.60 wt%, S: 0.040 wt% or less, P: 0.040 wt% or less, Ni: 0.015 to 0.025 wt%, Mo: 0.00 to 0.009 Weight%, Cu: 0.010-0.050 weight%, W: 0.00-0.005 weight%, V: 0.00-0.005 weight%, Ti: 0.00-0.005 weight%, B: 0.00-0.005 weight%, Other unavoidable impurities 0.96-0.98 weight % And the remaining Fe, the forged steel ball is heated to 1,150 ~ 1,200 ℃ and hot free forging (HOT FREE TYPE FORGING METHOD) before cooling to 950 ℃, the heat treatment method according to the diameter in detail is as follows .
After the forging steel ball diameter 66-75mm was subjected to isothermal heat treatment at 25-35 ℃ for 50 seconds after forging, it was immersed in the cooling water of 35 ± 5 ℃ at the temperature of 780 ± 10 ℃ for about 60-70 seconds. It undergoes a heat treatment process to naturally cool again at room temperature.
The diameter of the forged steel ball is 76 ~ 85mm after 45 ° isothermal heat treatment at 25 ~ 35 ℃ after forging, and then immersed in the cooling water of 35 ± 5 ℃ at the temperature of 780 ± 10 ℃ for about 75 ~ 85 seconds. It undergoes a heat treatment process to naturally cool again at room temperature.
After the forging, the diameter of 86 ~ 95mm is 45 ° C after isothermal heat treatment at 25 ~ 35 ℃ for forging, and then immersed in the cooling water of 35 ± 5 ℃ at 780 ± 10 ℃ for about 95 ~ 105 seconds. It undergoes a heat treatment process to naturally cool again at room temperature.
The diameter of the forged steel ball is 96 ~ 105mm after 50 minutes of isothermal heat treatment at 25 ~ 35 ℃ after forging, and then immersed in the cooling water of 35 ± 5 ℃ at the temperature of 780 ± 10 ℃ for about 105 ~ 125 seconds. It undergoes a heat treatment process to naturally cool again at room temperature.
After the forging, the diameter of 106-115mm for 50 seconds isothermally treated at 25-35 ℃ for forging, and then immersed in the cooling water of 35 ± 5 ℃ at 780 ± 10 ℃ for about 125-135 seconds. It undergoes a heat treatment process to naturally cool again at room temperature.
After the forging, the diameter of 116 ~ 125mm is subjected to isothermal heat treatment for 50 seconds at 25 ~ 35 ℃ after forging, and then immersed in the cooling water of 35 ± 5 ℃ at the temperature of 780 ± 10 ℃ for 135 ~ 145 seconds. It undergoes a heat treatment process to naturally cool again at room temperature.
The forged steel ball subjected to the above process is made of martensitic surface as shown in the texture picture of FIGS. 2A and 2B, and the core part has bainite structure to reduce internal and external hardness differences within HRC2 to 4. .
According to the above-described configuration of the present invention, as described above, according to the present invention, five major components of existing S-based simple high carbon steel, C, Mn, Si, Ni, P, S, Mo, Cr, Cu, W By using high-carbon alloy steel with altered or added combination ratio of V, Ti, B, etc. as a new material, forging work can minimize molding defects (incontinence, overlap) during hot forging, and also after heat treatment 2a and 2b form a martensite structure and bainite structure, having a finer structure than conventional forged steel ball, reducing the hardness difference between the core and the steel ball within HRC2 ~ 4 Create a new level of forged steel ball.
Therefore, the wear resistance can be increased more than twice as compared to the existing forged steel balls, and it is more environmentally friendly than the existing cast steel balls which contain 15 ~ 17% of chrome that is harmful to the environment. Excluding 6.4g of Cr per ton of 90mm cement, harmful chrome content can achieve the same durability even under rapid thermal changes.
Figure 1a is a martensite structure of the surface, the core portion is a 100 times magnified photograph of a conventional forged steel ball of pearlite tissue.
1B is a martensite structure on the surface, and the core portion is a 500 times magnified photograph of a conventional forged steel ball of pearlite structure.
Figure 2a is a martensite structure of the surface, the core is a 100 times magnified photograph of the forged steel ball of the present invention of bainite tissue.
Figure 2b is a martensite structure of the surface, the core portion is 500 times magnified photograph of the forged steel ball of the present invention of bainite tissue.
Hereinafter, with reference to the accompanying drawings will be described the component ratio of the forging steel ball used in the grinding mill (Mill) having the surface of the martensite structure and the deep part of the bainite structure, specific process embodiments and effects.
The present invention is to change the ratio of the five components of the S ** C-based high carbon steel of the existing material in weight%, forged steel balls (25), 35-35mm, 36-65mm, 66-120mm by classifying each The composition ratio of the composition is as shown in Table 1 below.
C: 0.40 to 0.65% by weight, Mn: 0.40 to 0.85% by weight, Si: 0.15 to 0.35% by weight, Cr: 0.25 to 1.00% by weight, S: 0.050% by weight, P: 0.050% by weight Ni: 0.015 to 0.025 weight%, Mo: 0.00 to 0.009 weight%, Cu: 0.010 to 0.050 weight%, W: 0.00 to 0.005 weight%, V: 0.00 to 0.005 weight%, Ti: 0.00 to 0.005 weight%, B: 0.00 ~ 0.005% by weight, other unavoidable impurities 0.96 ~ 0.98% by weight and alloy steel forgings composed of the remaining Fe.
C: 0.40 ~ 0.85% by weight, Mn: 0.60 ~ 1.10% by weight, Si: 0.00 ~ 1.80% by weight, Cr: 0.28 ~ 0.60% by weight, S: 0.040% by weight, P: 0.040% by weight Ni: 0.015 to 0.025 weight%, Mo: 0.00 to 0.009 weight%, Cu: 0.010 to 0.050 weight%, W: 0.00 to 0.005 weight%, V: 0.00 to 0.005 weight%, Ti: 0.00 to 0.005 weight%, B: 0.00 ~ 0.005% by weight, other unavoidable impurities 0.96 ~ 0.98% by weight and alloy steel forgings composed of the remaining Fe.
C: 0.72 to 0.82 weight%, Mn: 0.70 to 1.10 weight%, Si: 0.17 to 0.37 weight%, Cr: 0.28 to 0.60 weight%, S: 0.040 weight% or less, P: 0.040 weight% Ni: 0.015 to 0.025 weight%, Mo: 0.00 to 0.009 weight%, Cu: 0.010 to 0.050 weight%, W: 0.00 to 0.005 weight%, V: 0.00 to 0.005 weight%, Ti: 0.00 to 0.005 weight%, B: 0.00 ~ 0.005% by weight, other unavoidable impurities 0.96 ~ 0.98% by weight and alloy steel forgings composed of the remaining Fe.
After heating these new materials to 1,150 ~ 1,200 ℃ in a heating furnace, hot free forging (HOT FREE TYPE FORGING METHOD) is performed before cooling to 950 ℃, and after forging, isothermal heat treatment is performed and then cooled in cooling water. Here, the temperature during the isothermal heat treatment is carried out at 25 ~ 35 ℃.
Hot free forging is hammered at a speed of 65 ~ 66 times for 48 seconds with a pressure of 250kg with an air drop hammer before the material is heated to 950 ℃.
After forging, the isothermal heat treatment time and the time to be immersed in the coolant are based on Table 2.
The temperature of the coolant is 35 ± 5 ℃, the temperature of the raw material is 780 ± 10 ℃ and the coolant immersion time is shown in Table 2 above.
After the heat treatment process after the component ratio and hot forging process as described above, as shown in Figures 2a and 2b, the surface is composed of martensite structure, the core portion is composed of the bainite structure, the surface and core portion of the forged steel ball New forged steel balls with a hardness difference of HRC2-4 can be made.
Here, FIG. 2A is a 100 times picture and FIG. 2B is a 500 times picture.
The following describes a specific example of manufacturing a 90 mm diameter ball of forged steel ball used in a ball mill for grinding.
After cutting the new material of the component shown in Table 3 corresponding to the new high carbon alloy steel material shown in Table 1 above into a diameter of 65 mm and a length of 130 mm and heating it at 1,150 to 1,200 ° C. for 45 minutes and then cooling it to 950 ° C. on a hemispherical mold. Hot free forging that hammers at speed of 65 ~ 66 times for 48 seconds with 250kg of pressure with drop hammer produces forged steel ball of 90mm diameter.
When the forging operation is performed, a 90 mm forged steel ball having a minimum molding defect is produced when the forging operation is performed with simple S ** C series carbon steel suitable for conventional free forging.
The 90 mm forged steel ball is isothermalized for 45 seconds, and then obtained in coolant at 35 ° C. when it reaches 780 ± 10 ° C.
After immersing in the coolant for 95 ~ 105 seconds, the product reaching 180 ° C is removed from the coolant and subjected to a natural heat treatment at room temperature.
Through this entire process, as shown in Figure 2a and 2b, the outer portion is composed of martensite structure and the core portion of the bainite structure can be made a new forged steel ball (hardened steel ball) difference in hardness is within HRC2-4 .
At this time, if the alloy component or component ratio of Table 1 exceeds or falls below, the deep core structure of the ball is formed of pearlite as shown in Figure 1a and 1b can not overcome the hardness difference from the outside, or incontinence (fine crack) during the forging process This will occur.
Figure 2a is a 100-fold magnification, the surface of the martensite tissue picture is more dense than the martensite tissue of Figure 1a, the deeper bainite tissue is weaker than the martensite tissue or dense and stronger than the pearlite tissue of Figure 1b It shows that the tissue is formed, which can be seen in more detail in the 500 times magnification of Figure 2b.
According to the above description, if the heating temperature is 1,200 ° C. or higher or 1,150 ° C. or lower, a molding defect problem occurs, and internal cracks occur depending on the length and length of the isothermal heat treatment time (see Table 2) after hot forging. When the pressure is greater than 250kg, there is a disadvantage that the tissue is not dense, and when it is small, overlapping phenomenon occurs.
If the above-described component ratio is exceeded, cracks are present inside the tissue, and the ball is broken. If the component ratio is below the above-described component ratio, bainite tissue is not formed at the core and pearlite tissue is formed. These are those formed by the applicant's inexplicable experiment and experience.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, As will be understood by those skilled in the art. Therefore, it should be understood that the above-described embodiments are to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description, It is intended that all changes and modifications derived from the equivalent concept be included within the scope of the present invention.
Claims (10)
The forged steel ball is C: 0.40 to 0.65 weight%, Mn: 0.40 to 0.85 weight%, Si: 0.15 to 0.35 weight%, Cr: 0.25 to 1.00 weight%, S: 0.01 to 0.05 weight%, P: 0.01 to 0.05 weight %, Ni: 0.015-0.025 wt%, Mo: 0.001-0.009 wt%, Cu: 0.010-0.050 wt%, W: 0.001-0.005 wt%, V: 0.001-0.005 wt%, Ti: 0.001-0.005 wt%, B: 0.001 to 0.005% by weight, 0.96 to 0.98% by weight of other unavoidable impurities and the remaining Fe,
After the forged steel ball is heated to 1,150 ~ 1,200 ° C, hot free forging (HOT FREE TYPE FORGING METHOD) is performed until it is cooled to 950 ° C, and after forging, isothermal heat treatment is performed at 25-35 ° C for 13 to 30 seconds. After immersing in the cooling water of 35 ± 5 ℃ for 45 seconds at the temperature of 780 ± 10 ℃ of the forged steel ball, it undergoes a heat treatment process which naturally cools again at room temperature.The surface is composed of martensite structure and the core part has bainite structure. Forged steel ball for use in grinding mills (Mill), characterized in that to reduce the external hardness difference within HRC2 ~ 4.
The forged steel ball is C: 0.40 to 0.85 wt%, Mn: 0.60 to 1.10 wt%, Si: 0.01 to 1.80 wt%, Cr: 0.28 to 0.60 wt%, S: 0.01 to 0.04 wt%, P: 0.01 to 0.04 wt %, Ni: 0.015-0.025 wt%, Mo: 0.01-0.009 wt%, Cu: 0.010-0.050 wt%, W: 0.001-0.005 wt%, V: 0.001-0.005 wt%, Ti: 0.001-0.005 wt%, B: 0.001 to 0.005% by weight, 0.96 to 0.98% by weight of other unavoidable impurities and the remaining Fe,
After the forged steel ball is heated to 1,150 ~ 1,200 ° C, hot free forging (HOT FREE TYPE FORGING METHOD) is performed until it is cooled to 950 ° C. After immersing for 48 seconds in the cooling water of 35 ± 5 ℃ at 780 ± 10 ℃ and then naturally cooling it at room temperature, the surface is composed of martensite structure and the core part has bainite structure. Forged steel ball used for grinding mills having a surface of martensite structure and a deep part of bainite structure to reduce hardness difference within HRC2 ~ 4.
The forged steel ball is C: 0.40 to 0.85 wt%, Mn: 0.60 to 1.10 wt%, Si: 0.01 to 1.80 wt%, Cr: 0.28 to 0.60 wt%, S: 0.01 to 0.04 wt%, P: 0.01 to 0.04 wt %, Ni: 0.015-0.025 wt%, Mo: 0.001-0.009 wt%, Cu: 0.010-0.050 wt%, W: 0.001-0.005 wt%, V: 0.001-0.005 wt%, Ti: 0.001-0.005 wt%, B: 0.001 to 0.005% by weight, 0.96 to 0.98% by weight of other unavoidable impurities and the remaining Fe,
After the forged steel ball is heated to 1,150 ~ 1,200 ° C, hot free forging (HOT FREE TYPE FORGING METHOD) is performed until it is cooled to 950 ° C, and the forged steel ball is subjected to isothermal heat treatment at 25 ~ 35 ° C for 27 seconds after forging. After immersed in a cooling water of 35 ± 5 ℃ at a temperature of 780 ± 10 ℃ for 50 seconds and then natural cooling again at room temperature, the surface is composed of martensite structure and the core part has a bainite structure to the inside and outside Forged steel ball used for grinding mills having a surface of martensite structure and a deep part of bainite structure to reduce hardness difference within HRC2 ~ 4.
The forged steel ball is C: 0.40 to 0.85 wt%, Mn: 0.60 to 1.10 wt%, Si: 0.01 to 1.80 wt%, Cr: 0.28 to 0.60 wt%, S: 0.040 wt% or less, P: 0.01 to 0.040 wt% , Ni: 0.015-0.025 wt%, Mo: 0.001-0.009 wt%, Cu: 0.010-0.050 wt%, W: 0.001-0.005 wt%, V: 0.001-0.005 wt%, Ti: 0.001-0.005 wt%, B : 0.001 to 0.005 weight percent, 0.96 to 0.98 weight percent of other unavoidable impurities, and the remaining Fe,
After the forged steel ball is heated to 1,150 ~ 1,200 ° C, hot free forging (HOT FREE TYPE FORGING METHOD) is performed until it is cooled to 950 ° C, and the forged steel ball is subjected to isothermal heat treatment at 25 ~ 35 ° C for 25 seconds after forging. After immersed in a cooling water of 35 ± 5 ℃ at a temperature of 780 ± 10 ℃ for 50-55 seconds, and then subjected to a heat treatment process to naturally cool again at room temperature, the surface is composed of martensite structure and the core part has a bainite structure Forged steel ball for use in grinding mills having the surface of martensite structure and the deep part of bainite structure to reduce external hardness difference within HRC2 ~ 4.
The forged steel ball is C: 0.72 to 0.82 weight%, Mn: 0.70 to 1.10 weight%, Si: 0.17 to 0.37 weight%, Cr: 0.28 to 0.60 weight%, S: 0.01 to 0.040 weight%, P: 0.01 to 0.040 weight %, Ni: 0.015-0.025 wt%, Mo: 0.001-0.009 wt%, Cu: 0.010-0.050 wt%, W: 0.001-0.005 wt%, V: 0.001-0.005 wt%, Ti: 0.001-0.005 wt%, B: 0.001 to 0.005% by weight, 0.96 to 0.98% by weight of other unavoidable impurities and the remaining Fe,
After the forged steel ball is heated to 1,150 ~ 1,200 ° C, hot free forging (HOT FREE TYPE FORGING METHOD) is performed until it is cooled down to 950 ° C. After immersing in the cooling water of 35 ± 5 ℃ at 780 ± 10 ℃ for 60 ~ 70 seconds, it undergoes a heat treatment process that naturally cools it again at room temperature.The surface is composed of martensite structure and the core has bainite structure. Forged steel ball for use in grinding mills having the surface of martensite structure and the deep part of bainite structure to reduce external hardness difference within HRC2 ~ 4.
The forged steel ball is C: 0.72 to 0.82 weight%, Mn: 0.70 to 1.10 weight%, Si: 0.17 to 0.37 weight%, Cr: 0.28 to 0.60 weight%, S: 0.01 to 0.040 weight%, P: 0.01 to 0.040 weight %, Ni: 0.015-0.025 wt%, Mo: 0.001-0.009 wt%, Cu: 0.010-0.050 wt%, W: 0.001-0.005 wt%, V: 0.001-0.005 wt%, Ti: 0.001-0.005 wt%, B: 0.001 to 0.005% by weight, 0.96 to 0.98% by weight of other unavoidable impurities and the remaining Fe,
After the forged steel ball is heated to 1,150 ~ 1,200 ° C, hot free forging (HOT FREE TYPE FORGING METHOD) is performed until it is cooled to 950 ° C, and the forged steel ball is subjected to isothermal heat treatment at 25 ~ 35 ° C for 45 seconds after forging. It is immersed in the cooling water of 35 ± 5 ℃ at 780 ± 10 ℃ for 75 ~ 85 seconds and then subjected to a heat treatment process that naturally cools again at room temperature.The surface is composed of martensite structure and the core has bainite structure. Forged steel ball for use in grinding mills having the surface of martensite structure and the deep part of bainite structure to reduce external hardness difference within HRC2 ~ 4.
The forged steel ball is C: 0.72 to 0.82 weight%, Mn: 0.70 to 1.10 weight%, Si: 0.17 to 0.37 weight%, Cr: 0.28 to 0.60 weight%, S: 0.01 to 0.040 weight%, P: 0.01 to 0.040 weight %, Ni: 0.015-0.025 wt%, Mo: 0.001-0.009 wt%, Cu: 0.010-0.050 wt%, W: 0.001-0.005 wt%, V: 0.001-0.005 wt%, Ti: 0.001-0.005 wt%, B: 0.001 to 0.005% by weight, 0.96 to 0.98% by weight of other unavoidable impurities and the remaining Fe,
After the forged steel ball is heated to 1,150 ~ 1,200 ° C, hot free forging (HOT FREE TYPE FORGING METHOD) is performed until it is cooled down to 950 ° C. After immersed in the cooling water of 35 ± 5 ℃ at 780 ± 10 ℃ for 95 ~ 105 seconds and undergoing a heat treatment to naturally cool again at room temperature, the surface is composed of martensite structure and the core has bainite structure. Forged steel ball for use in grinding mills having the surface of martensite structure and the deep part of bainite structure to reduce external hardness difference within HRC2 ~ 4.
The forged steel ball is C: 0.72 to 0.82 weight%, Mn: 0.70 to 1.10 weight%, Si: 0.17 to 0.37 weight%, Cr: 0.28 to 0.60 weight%, S: 0.01 to 0.040 weight%, P: 0.01 to 0.040 weight %, Ni: 0.015-0.025 wt%, Mo: 0.001-0.009 wt%, Cu: 0.010-0.050 wt%, W: 0.001-0.005 wt%, V: 0.001-0.005 wt%, Ti: 0.001-0.005 wt%, B: 0.001 to 0.005% by weight, 0.96 to 0.98% by weight of other unavoidable impurities and the remaining Fe,
After the forged steel ball is heated to 1,150 ~ 1,200 ° C, hot free forging (HOT FREE TYPE FORGING METHOD) is performed before cooling to 950 ° C, and after forging, the isothermal heat treatment is performed at 25 ~ 35 ° C for 50 seconds, and then the forged steel ball It is immersed in the cooling water of 35 ± 5 ℃ at 780 ± 10 ℃ for 105 ~ 125 seconds and then subjected to a heat treatment process that naturally cools again at room temperature.The surface is composed of martensite structure and the core has bainite structure. Forged steel ball for use in grinding mills having the surface of martensite structure and the deep part of bainite structure to reduce external hardness difference within HRC2 ~ 4.
The forged steel ball is C: 0.72 to 0.82 weight%, Mn: 0.70 to 1.10 weight%, Si: 0.17 to 0.37 weight%, Cr: 0.28 to 0.60 weight%, S: 0.01 to 0.040 weight%, P: 0.01 to 0.040 weight %, Ni: 0.015-0.025 wt%, Mo: 0.001-0.009 wt%, Cu: 0.010-0.050 wt%, W: 0.001-0.005 wt%, V: 0.001-0.005 wt%, Ti: 0.001-0.005 wt%, B: 0.001 to 0.005% by weight, 0.96 to 0.98% by weight of other unavoidable impurities and the remaining Fe,
After the forged steel ball is heated to 1,150 ~ 1,200 ° C, hot free forging (HOT FREE TYPE FORGING METHOD) is performed until it is cooled down to 950 ° C. After immersing in the cooling water of 35 ± 5 ℃ at 780 ± 10 ℃ for 125 ~ 135 seconds and undergoing a heat treatment to naturally cool again at room temperature, the surface is composed of martensite structure and the core has bainite structure. Forged steel ball for use in grinding mills having the surface of martensite structure and the deep part of bainite structure to reduce external hardness difference within HRC2 ~ 4.
The forged steel ball is C: 0.72 to 0.82 weight%, Mn: 0.70 to 1.10 weight%, Si: 0.17 to 0.37 weight%, Cr: 0.28 to 0.60 weight%, S: 0.01 to 0.040 weight%, P: 0.01 to 0.040 weight %, Ni: 0.015-0.025 wt%, Mo: 0.001-0.009 wt%, Cu: 0.010-0.050 wt%, W: 0.001-0.005 wt%, V: 0.001-0.005 wt%, Ti: 0.001-0.005 wt%, B: 0.001 to 0.005% by weight, 0.96 to 0.98% by weight of other unavoidable impurities and the remaining Fe,
After the forged steel ball is heated to 1,150 ~ 1,200 ° C, hot free forging (HOT FREE TYPE FORGING METHOD) is performed until it is cooled down to 950 ° C. After immersing in coolant of 35 ± 5 ℃ at 780 ± 10 ℃ for 35 ~ 145 seconds and undergoing natural heat treatment again at room temperature, the surface is composed of martensite structure and the core has bainite structure. Forged steel ball used as grinding mill having the surface of martensite structure and the deep part of bainite structure to reduce external hardness difference within HRC2 ~ 4.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110819897A (en) * | 2019-11-14 | 2020-02-21 | 伊莱特能源装备股份有限公司 | Material and method suitable for producing large-diameter wear-resistant steel balls of semi-autogenous mill |
| CN114892086A (en) * | 2022-05-07 | 2022-08-12 | 安徽新马铸造科技有限公司 | Corrosion-resistant high-strength wear-resistant steel ball |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2973010B2 (en) | 1989-11-30 | 1999-11-08 | エヌティエヌ株式会社 | Grease-sealed steel balls for bearings |
| JP2004225073A (en) | 2003-01-20 | 2004-08-12 | Sumitomo Metal Ind Ltd | Non-heat treated bar steel for hot forging |
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2012
- 2012-02-02 KR KR1020120010672A patent/KR101169654B1/en active IP Right Grant
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2973010B2 (en) | 1989-11-30 | 1999-11-08 | エヌティエヌ株式会社 | Grease-sealed steel balls for bearings |
| JP2004225073A (en) | 2003-01-20 | 2004-08-12 | Sumitomo Metal Ind Ltd | Non-heat treated bar steel for hot forging |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110819897A (en) * | 2019-11-14 | 2020-02-21 | 伊莱特能源装备股份有限公司 | Material and method suitable for producing large-diameter wear-resistant steel balls of semi-autogenous mill |
| CN110819897B (en) * | 2019-11-14 | 2021-08-31 | 伊莱特能源装备股份有限公司 | Material and method suitable for producing large-diameter wear-resistant steel balls of semi-autogenous mill |
| CN114892086A (en) * | 2022-05-07 | 2022-08-12 | 安徽新马铸造科技有限公司 | Corrosion-resistant high-strength wear-resistant steel ball |
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