阅读说明：本技术 一种添加半金属的强韧高铬铸铁磨片 (Tough high-chromium cast iron abrasive disc added with semimetal ) 是由 严震 蒋小军 徐桂军 孙靖菲 赵杨 蒋思蒙 宋萍 吴佳严 于 2020-06-04 设计创作，主要内容包括：本发明公开一种添加半金属的强韧高铬铸铁磨片,包括磨片材料,其特征在于,所述磨片材料中添加微量的半金属碲、锑、硼和微量稀有金属铌、钛,用于促进高铬铸铁的晶粒细化、淬透性、硬度、韧性的发展,主要包括四个步骤,1)磨片的铸造；2)磨片的热处理；3)磨片的冷却处理；4)磨片的后续处理。本发明的磨片基体硬度60-64HRC,磨片齿条表面硬度61-66HRC,冲击功达8.5-12J/cm～(2),其硬度、冲击韧度及耐磨性均得到提升,磨片实现了强度与韧性的良好配合,在工作中具有高韧性、高耐磨性的磨片,适应磨机恶劣的工况条件,提高磨片使用寿命和纤维素纤维制备质量。(The invention discloses a tough high-chromium cast iron grinding plate added with semimetal, which comprises a grinding plate material and is characterized in that trace semimetal tellurium, antimony and boron and trace rare metals niobium and titanium are added into the grinding plate material for promoting the development of grain refinement, hardenability, hardness and toughness of high-chromium cast iron, and the method mainly comprises four steps of 1) casting the grinding plate; 2) heat treatment of the grinding sheet; 3) cooling the grinding plate; 4) and (5) performing subsequent treatment on the grinding sheet. The hardness of the grinding sheet matrix is 60-64HRC, the surface hardness of the grinding sheet rack is 61-66HRC, and the impact power reaches 8.5-12J/cm 2 The hardness, impact toughness and wear resistance of the abrasive disc are improved, the abrasive disc realizes good matching of strength and toughness, and has high toughness in workThe grinding disc with high wear resistance adapts to the severe working condition of the grinding machine, and the service life of the grinding disc and the preparation quality of cellulose fibers are improved.)

1. The high-toughness high-chromium cast iron grinding plate added with the semimetal comprises a grinding plate material and is characterized in that the grinding plate material comprises the following components in percentage by weight: 2.8 to 3.8 percent of carbon, 0.6 to 1.2 percent of silicon, 0.5 to 1.1 percent of manganese, 26 to 35 percent of chromium, 1.15 to 2.55 percent of molybdenum, 0.35 to 0.45 percent of nickel, 0.85 to 2.35 percent of copper, 0.1 to 0.3 percent of titanium, 0.2 to 0.4 percent of vanadium, 0.05 to 0.12 percent of boron, 0.02 to 0.03 percent of antimony, 0.06 to 0.12 percent of niobium, 0.0005 to 0.0015 percent of tellurium, and the balance of iron.

2. The high-toughness high-chromium cast iron grinding plate added with semimetals according to claim 1, characterized in that trace semimetals of tellurium, antimony and boron and trace rare metals of niobium and titanium are added into the grinding plate material for promoting the development of grain refinement, hardenability, hardness and toughness of the high-chromium cast iron.

3. The tough high-chromium cast iron grinding chip added with semimetal according to the claims 1 and 2, characterized in that the specific preparation method comprises the following steps:

1) casting the grinding sheet: smelting in a medium-frequency induction furnace at 1420 ℃ and 1500 ℃, discharging, and casting and molding by using a sand-coated metal mold to prepare a grinding sheet blank;

2) and (3) heat treatment of the grinding sheet: quenching the formed grinding sheet blank twice, wherein isothermal quenching is carried out for 1.5-2.5 hours for the first time at the temperature of 950-; the isothermal quenching for the second time is 1 to 1.5 hours at the temperature of 280 ℃ and 350 ℃;

3) cooling treatment of the grinding sheet: embedding the back surface of the grinding plate into heat-insulating sand while the back surface of the grinding plate is hot, exposing the tooth surface, and adopting a cooling method combining air cooling and air cooling, wherein the cooling method can directionally align the tooth surface of the grinding plate to accelerate the cooling of the tooth surface, so that the hardness of a grinding plate matrix reaches 60-64 HRC; the surface of the grinding sheet rack can be cooled more quickly due to smaller surface area, so that the surface of the rack has higher hardness, the surface hardness of the rack is 1-2HRC higher than that of a base body, and the impact energy reaches 8.5-12J/cm²The service life is longer;

4) and (3) post-processing of the grinding sheet: after cooling treatment, the product is prepared by shot blasting and polishing treatment.

4. The method for preparing the tough high-chromium cast iron grinding disc added with the semimetal according to the claim 3, characterized in that in the step 2, two times of continuous isothermal quenching are used for changing the solidification process of the high-chromium cast iron, refining crystal grains and reducing the defects of shrinkage cavity and porosity.

5. The method for preparing the tough high-chromium cast iron grinding chip added with the semimetal according to the claim 3, characterized in that in the step 3, the hardness of the surface of the rack is 61-66 HRC.

6. The method for preparing the tough high-chromium cast iron grinding chip added with the semimetal according to the claim 3, characterized in that in the step 3, the grinding chip base structure is martensite + lower bainite + retained austenite.

Technical Field

The invention belongs to the technical field of artificial boards and pulping and papermaking, and particularly relates to a tough high-chromium cast iron grinding plate added with semimetal.

Background

Artificial boards and mill grinding discs in the pulp and paper industry are components for directly separating cellulose fibers. When the fibers are separated, the grinding machine is also worn, and whether the grinding machine can fully exert the technical performance and the economic index depends on the wearing state of the grinding sheet to a great extent. In the process of separating cellulose fibers, the abrasive disc can generate friction abrasion, fatigue abrasion, abrasive particle abrasion, corrosion abrasion and the like, and after the abrasive disc is abraded, the cutting edge is passivated, the gap is enlarged, and the abrasive disc is made to be out of operation. The hardness of the stainless steel abrasive material in the prior art is usually 25-45HRC, the toughness is good, but the wear resistance is poor; the hardness of the high-chromium cast iron abrasive disc material is usually 50-60HRC, and the abrasive disc in the prior art has high hardness and good wear resistance but poor toughness.

The wear of the grinding plate in a service cycle is divided into 3 different stages, wherein the 1 st stage is an early grinding-in stage, the 2 nd stage is a normal working stage, and the 3 rd stage is a later passivation stage. The macroscopic phenomenon of abnormal abrasion of the abrasive disc with poor toughness is large-area tooth breakage, and the damage form directly influences production, so that the consequence is serious; and after the grinding disc with low hardness and poor wear resistance is ground for a short time, the grinding disc rack enters a passivation stage in advance, so that the grinding disc is taken off in advance due to unqualified quality of separated fibers, and the service life of the grinding disc is seriously shortened.

Therefore, the grinding plate with high toughness and high wear resistance needs to be designed and developed to adapt to the severe working conditions of the grinding machine.

Disclosure of Invention

The invention aims to provide a tough high-chromium cast iron grinding disc added with semimetal, which aims to solve the problem that the grinding disc with poor toughness and wear resistance, which is proposed in the background art, is easy to cause serious shortening of the service life.

In order to achieve the purpose, the invention provides the following technical scheme: the high-toughness high-chromium cast iron grinding plate added with the semimetal comprises a grinding plate material and is characterized in that the grinding plate material comprises the following components in percentage by weight: 2.8 to 3.8 percent of carbon, 0.6 to 1.2 percent of silicon, 0.5 to 1.1 percent of manganese, 26 to 35 percent of chromium, 1.15 to 2.55 percent of molybdenum, 0.35 to 0.45 percent of nickel, 0.85 to 2.35 percent of copper, 0.1 to 0.3 percent of titanium, 0.2 to 0.4 percent of vanadium, 0.05 to 0.12 percent of boron, 0.02 to 0.03 percent of antimony, 0.06 to 0.12 percent of niobium, 0.0005 to 0.0015 percent of tellurium, and the balance of iron.

Preferably, trace amounts of semimetals of tellurium, antimony and boron and trace amounts of rare metals of niobium and titanium are added into the abrasive disc material for promoting the development of grain refinement, hardenability, hardness and toughness of the high-chromium cast iron.

Preferably, the specific preparation method comprises the following steps:

1) casting the grinding sheet: smelting in a medium-frequency induction furnace at 1420 ℃ and 1500 ℃, discharging, and casting and molding by using a sand-coated metal mold to prepare a grinding sheet blank;

2) and (3) heat treatment of the grinding sheet: quenching the formed grinding sheet blank twice, wherein isothermal quenching is carried out for 1.5-2.5 hours for the first time at the temperature of 950-; the isothermal quenching for the second time is 1 to 1.5 hours at the temperature of 280 ℃ and 350 ℃;

3) cooling treatment of the grinding sheet: embedding the back surface of the grinding plate into heat-insulating sand while the back surface of the grinding plate is hot, exposing the tooth surface, and adopting a cooling method combining air cooling and air cooling, wherein the cooling method can directionally align the tooth surface of the grinding plate to accelerate the cooling of the tooth surface, so that the hardness of a grinding plate matrix reaches 60-64 HRC; the surface of the grinding sheet rack can be cooled more quickly due to smaller surface area, so that the surface of the rack has higher hardness, the surface hardness of the rack is 1-2HRC higher than that of a base body, and the impact energy reaches 8.5-12J/cm²The service life is longer;

4) and (3) post-processing of the grinding sheet: after cooling treatment, the product is prepared by shot blasting and polishing treatment.

In the step 2, two times of continuous isothermal quenching are used for changing the solidification process of the high-chromium cast iron, refining crystal grains and reducing the defects of shrinkage cavity and porosity.

In step 3, the surface hardness of the rack is 61-66 HRC.

In step 3, the grinding plate matrix structure is martensite, lower bainite and retained austenite.

Compared with the prior art, the invention has the beneficial effects that:

the hardness of the grinding sheet matrix is 60-64HRC, the surface hardness of the grinding sheet rack is 61-66HRC, and the impact power reaches 8.5-12J/cm²Its hardness, impact toughness and wearability all obtain promoting, and the abrasive disc has realized the good cooperation of intensity with toughness, has the abrasive disc of high toughness, high wearability in the work, adapts to the abominable operating mode condition of mill, improves abrasive disc life and cellulose fiber preparation quality.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

In the figure: 1. grinding; 2. a substrate; 3. a rack surface.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

according to the principle and the technical scheme of the invention, the chemical components are determined as follows: 3.8% of carbon, 0.9% of silicon, 0.8% of manganese, 32% of chromium, 1.6% of molybdenum, 0.4% of nickel, 1.6% of copper, 0.25% of titanium, 0.3% of vanadium, 0.09% of boron, 0.025% of antimony, 0.09% of niobium, 0.0012% of tellurium and the balance of iron.

Step one, casting of a grinding sheet:

smelting in a medium-frequency induction furnace, discharging at 1480 ℃, and casting and molding by using a sand-coated metal mold to prepare the abrasive disc blank.

Step two, heat treatment of the grinding plate:

quenching the formed grinding plate blank twice, wherein the first isothermal quenching is carried out for 2 hours at the temperature of 960 ℃; the second austempering was carried out for 1 hour at a temperature of 350 ℃. And two times of continuous isothermal quenching are used for changing the solidification process of the high-chromium cast iron, refining crystal grains and reducing the defects of shrinkage cavity and looseness.

Step three, cooling treatment of the grinding plate:

embedding the back surface of the grinding plate 1 into heat-insulating sand while the back surface is hot to expose the tooth surface, and adopting a cooling method combining air cooling and air cooling, wherein the cooling method can directionally align the tooth surface of the grinding plate to accelerate the cooling of the tooth surface, so that the hardness of a grinding plate base body 2 reaches 64 HRC; the surface 3 of the grinding sheet rack can be cooled more quickly due to smaller area, so that the surface 3 of the rack has higher hardness, the hardness of the surface 3 of the rack is 1HRC higher than that of the base body 2 and reaches 65HRC, and the impact power reaches 9.8J/cm²And the service life is longer. The structure of the grinding plate matrix 2 is martensite, lower bainite and retained austenite, the hardness, impact toughness and wear resistance of the grinding plate matrix are improved, and the grinding plate realizes good matching of strength and toughness.

Step four, post-processing of grinding plates:

after cooling treatment, the abrasive disc is prepared by shot blasting and polishing treatment, and the abrasive disc prepared in the way has the advantages of low abrasion loss, high toughness, scouring resistance, cavitation resistance, corrosion resistance and the like during working.

Example 2:

according to the principle and the technical scheme of the invention, the chemical components are determined as follows: 3.6% of carbon, 0.8% of silicon, 0.7% of manganese, 26% of chromium, 1.25% of molybdenum, 0.35% of nickel, 1.8% of copper, 0.20% of titanium, 0.35% of vanadium, 0.1% of boron, 0.02% of antimony, 0.08% of niobium, 0.001% of tellurium and the balance of iron.

Step one, casting of a grinding sheet:

smelting in a medium-frequency induction furnace at 1450 ℃, discharging, and casting and molding by using a sand-coated metal mold to prepare the abrasive disc blank.

Step two, heat treatment of the grinding plate:

quenching the formed abrasive disc blank twice, wherein the first isothermal quenching is carried out for 1.5 hours at the temperature of 980 ℃; the second austempering was carried out for 1.5 hours at a temperature of 320 ℃. And two times of continuous isothermal quenching are used for changing the solidification process of the high-chromium cast iron, refining crystal grains and reducing the defects of shrinkage cavity and looseness.

Step three, cooling treatment of the grinding plate:

embedding the back surface of the grinding plate 1 into heat-insulating sand while the back surface is hot to expose the tooth surface, and adopting a cooling method combining air cooling and air cooling, wherein the cooling method can be directionally aligned with the tooth surface of the grinding plate to accelerate the cooling of the tooth surface, so that the hardness of a grinding plate base body 2 reaches 62 HRC; the surface 3 of the grinding sheet rack can be cooled more quickly due to smaller area, so the surface 3 of the grinding sheet rack has higher hardness, the hardness of the surface 3 of the rack is 1.5HRC higher than that of the base body 2 and reaches 63.5HRC, and the impact power reaches 8.5J/cm²And the service life is longer. The structure of the grinding plate matrix 2 is martensite, lower bainite and retained austenite, the hardness, impact toughness and wear resistance of the grinding plate matrix are improved, and the grinding plate realizes good matching of strength and toughness.

Step four, post-processing of grinding plates:

after cooling treatment, the abrasive disc is prepared by shot blasting and polishing treatment, and the abrasive disc prepared in the way has the advantages of low abrasion loss, high toughness, scouring resistance, cavitation resistance, corrosion resistance and the like during working.

Example 3:

according to the principle and the technical scheme of the invention, the chemical components are determined as follows: 3.4% of carbon, 1.0% of silicon, 0.6% of manganese, 28% of chromium, 1.45% of molybdenum, 0.45% of nickel, 2.1% of copper, 0.18% of titanium, 0.25% of vanadium, 0.08% of boron, 0.028% of antimony, 0.1% of niobium, 0.0015% of tellurium and the balance of iron.

Step one, casting of a grinding sheet:

smelting in a medium-frequency induction furnace at 1470 ℃, discharging, and casting and molding by using a sand-coated metal mold to obtain the abrasive disc blank.

Step two, heat treatment of the grinding plate:

quenching the formed grinding sheet blank twice, wherein the first isothermal quenching is carried out for 2 hours at the temperature of 1000 ℃; the second austempering was carried out for 1 hour at a temperature of 340 ℃. And two times of continuous isothermal quenching are used for changing the solidification process of the high-chromium cast iron, refining crystal grains and reducing the defects of shrinkage cavity and looseness.

Step three, cooling treatment of the grinding plate:

embedding the back of the abrasive disc 1 into heat-insulating sand while the abrasive disc is hot, exposing the tooth surface, and adopting the superposition combination of air cooling and air coolingA cooling method which can directionally align the cooling of the tooth surface accelerating tooth surface of the grinding plate so as to ensure that the hardness of the grinding plate base body 2 reaches 63.5 HRC; the surface 3 of the grinding sheet rack can be cooled more quickly due to smaller area, so that the surface 3 of the grinding sheet rack has higher hardness, the hardness of the surface 3 of the rack is higher than that of the base body 2 by 2HRC and reaches 65.5HRC, and the impact power reaches 10.1J/cm²And the service life is longer. The structure of the grinding plate matrix 2 is martensite, lower bainite and retained austenite, the hardness, impact toughness and wear resistance of the grinding plate matrix are improved, and the grinding plate realizes good matching of strength and toughness.

Step four, post-processing of grinding plates:

after cooling treatment, the abrasive disc is prepared by shot blasting and polishing treatment, and the abrasive disc prepared in the way has the advantages of low abrasion loss, high toughness, scouring resistance, cavitation resistance, corrosion resistance and the like during working.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.