High speed steel centrifugal composite roller bonding layer quality defect control method

Abstract

The application discloses a high-speed steel centrifugal composite roller bonding layer quality defect control method, which comprises the following steps: preparing high-speed steel roller outer layer molten steel by adopting low-sulfur-content raw materials to avoid desulfurization operation during smelting, adjusting chemical elements of the high-speed steel roller outer layer molten steel which are not easy to oxidize, discharging the molten steel with slag and gathering the slag, adjusting the composition of the molten steel by remelting to adjust the chemical elements which are easy to oxidize, discharging the molten steel with slag, pretreating the molten steel by using Re and carbon powder, and pouring in a closed ladle with a bottom leakage package. The high-speed steel roller is poured in a "three-temperature and three-time" mode. The application can effectively control the equivalent defects, improve the bonding quality of the high-speed steel roller, improve the qualified rate of the high-speed steel roller, and ensure the safe use of the high-speed steel roller.

Description

Technical Field

[0001] This invention relates to the field of casting technology, and in particular to a method for controlling quality defects in the bonding layer of high-speed steel centrifugal composite rolls. Background Technology

[0002] High-speed steel is short for high-speed tool steel. Currently, most large-scale casting roll manufacturers at home and abroad use centrifugal casting to produce high-speed steel composite work rolls required for hot-rolled strip continuous rolling mills.

[0003] The key to producing high-speed steel rolls using a composite method is to prevent a large amount of alloying elements from penetrating into the core layer of the roll working layer, thereby reducing the overall performance of the roll shaft.

[0004] For any roll manufacturer, the design of the outer, middle, and core layers of high-speed steel rolls using a composite production method is no longer a technical secret when modern testing technology is employed. The most critical aspect is the quality control of the bonding layer. This not only affects the product qualification rate of high-speed steel rolls but also their safe use on the rolling mill.

[0005] Quality control of the centrifugal composite roll bonding layer involves both the strength of the centrifugal composite roll bonding layer and the control of quality defects in the centrifugal composite roll bonding layer.

[0006] Chinese invention patent CN 104525889 A discloses a method for manufacturing high-speed steel rolls for small steel rolling mills and wire rod rolling mills. It only mentions obtaining the high strength performance of the centrifugal composite bonding layer, but does not mention how to control the quality defects of the bonding layer.

[0007] The issue of bonding strength in centrifugal composite rolls can be addressed through the design of the inner and outer layers' process composition and the control of casting parameters. However, controlling the quality defects of the bonding layer involves multiple aspects, including molten iron smelting, slag removal, casting protection, and effective control of casting parameters. This invention proposes a method for controlling the quality defects of the bonding layer in high-speed steel centrifugal composite rolls. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a method for controlling the quality defects of the bonding layer of high-speed steel centrifugal composite rolls, which effectively controls the existence of equivalent defects, improves the bonding quality of high-speed steel rolls, and ensures the safe use of high-speed steel rolls while increasing the manufacturing qualification rate of high-speed steel rolls.

[0009] To achieve the above objectives, the present invention employs the following technical solution:

[0010] A method for controlling quality defects in the bonding layer of high-speed steel centrifugal composite rolls includes the following:

[0011] 1) Preparation of the outer layer of molten steel for high-speed steel rolls:

[0012] a) The outer layer of high-speed steel rolls is smelted using raw materials with low sulfur content to avoid desulfurization operations during the smelting process due to the high sulfur content of the outer layer of high-speed steel rolls; the sulfur content of the outer layer of high-speed steel rolls is controlled at <0.018wt%.

[0013] b) The outer layer of high-speed steel rolls is made of melted steel raw materials. Except for the easily oxidized chemical components, all other alloy components are adjusted to meet the process requirements. The aluminum content in the purchased easily oxidized alloy raw materials is controlled below 1.0 wt%.

[0014] c) After the outer layer of high-speed steel is heated to 1500-1580℃, it is completely transferred from the smelting furnace into the ladle. The slag thinner should be evenly placed at the bottom of the ladle beforehand for slag thinning. The amount of slag thinner added is 0.20wt% to 1.0wt% of the total amount of molten steel discharged from the furnace.

[0015] d) After the slag thinning operation is completed, skim off the floating slag from the surface of the molten steel and use a slag-forming agent to form slag. The amount of slag-forming agent added should be enough to completely cover the surface of the molten steel.

[0016] e) Adjusting the easily oxidizable chemical composition by remelting the molten steel: Add 10wt%–40wt% of preheated alloy material with easily oxidizable chemical components to the bottom of the furnace. After removing the slag buildup on the surface of the molten steel, quickly return the outer layer of high-speed steel to the furnace. Add the remaining preheated alloy material with easily oxidizable chemical components to the surface of the molten steel. Once all the easily oxidizable chemical components have melted, raise the temperature of the molten steel to 1490–1600℃ and let it stand for 30–60 minutes with slag, awaiting tapping.

[0017] f) When the outer layer of molten steel from the high-speed steel roll is discharged from the furnace, the molten steel is pretreated with Re and carbon powder. The total amount of Re and carbon powder added is 0.20wt% to 0.50wt% of the total amount of molten steel, and aluminum cake deoxidation is eliminated.

[0018] g) The pouring temperature of the outer layer of molten steel for high-speed steel rolls is 1400~1500℃.

[0019] 2) Control of the interval between the preparation and pouring of molten steel in the middle layer of high-speed steel rolls:

[0020] a) The carbon content of the molten steel in the middle layer of the high-speed steel roll is <2.0wt%; ordinary carbon rust-free scrap steel is strictly used for batching, and various alloy rusted scrap steels are strictly prohibited from use.

[0021] b) The smelting and tapping of the middle layer of high-speed steel rolls shall be carried out in accordance with the conventional graphite steel smelting process, and the pouring temperature of the middle layer of high-speed steel rolls shall be 1480~1560℃.

[0022] c) Control of the interval time for pouring the middle layer of high-speed steel rolls: The middle layer of molten steel should be poured 4 to 18 minutes after the outer layer of molten steel is poured.

[0023] 3) Control of total condensation time of molten steel in the outer and middle layers of high-speed steel rolls: The roll cooling is terminated on the premise that no molten steel drips when the centrifuge is reduced and stopped.

[0024] 4) Roll core filling speed and temperature control: After stopping the roll cooling, quickly close the box for core filling. The selection of roll core filling temperature is based on the roll middle layer material. Under the premise of avoiding the penetration of the roll middle layer material alloy into the core layer molten iron during roll core filling, the core layer pouring temperature should be increased as much as possible.

[0025] Rapidly assemble the roll and fill the core. Since the middle layer material of the high-speed steel roll is graphite steel, the long assembly time and low filling temperature can easily lead to point defects in the bonding layer between the middle layer and the core layer of the roll, resulting in poor metallurgical bonding quality.

[0026] The selection of roll core-filling temperature, combined with the roll's middle layer material, aims to maximize the pouring temperature while preventing excessive penetration of the middle layer alloy into the core layer molten iron. Determining the correctness of the roll core-filling pouring temperature process parameters requires simulated production testing of the first piece. Firstly, it must be ensured that there are no excessive equivalent defects in the "middle-core" bonding layer of the high-speed steel roll; secondly, a handheld spectrometer is used to detect that the total "W+Cr+Mo" alloy content of the finished roll shaft is <0.8%, ultimately determining the roll core-filling pouring temperature. Considering these factors, this invention designs the high-speed steel roll tooling assembly time to be <10 minutes, the roll core-filling temperature to be controlled between 1380 and 1460℃, and the core-filling speed to be controlled between 40 and 100 kg / s.

[0027] The quality defects in the bonding layer of centrifugal composite rolls fall into two main categories. One is the presence of metallic and non-metallic oxide foreign matter in the bonding layer, exceeding the equivalent defect standard; the other is delamination due to incomplete fusion of the inner and outer metallurgical bonds. Eliminating non-metallic foreign matter in the roll bonding layer primarily requires controlling and resolving its source. Regarding controlling the metallurgical bonding quality problems of the inner and outer layers of centrifugal composite rolls, the most crucial factor is the reasonable and effective control of the casting parameters for both the inner and outer layers.

[0028] For high-speed roll production quality control, the smelting operation of the outer and middle layers of molten steel is crucial to effectively control the formation of metallic and non-metallic oxides in the roll bonding layer. This invention employs refined feedstock smelting for the outer layer of high-speed steel rolls, minimizing the need for steel desulfurization. After the molten steel is melted and the alloying of non-oxidizable chemical elements is completed, a thinning agent is used to thin the slag outside the furnace, followed by slag agglomeration and cleaning. The molten steel is then returned to the furnace for a one-time addition of easily oxidizable alloying elements at a moderate temperature. After all the easily oxidizable alloying materials have melted, the temperature is raised to 1490–1600°C, the power is cut off, and the molten steel is allowed to stand for 30–60 minutes. The outer layer of molten steel for the high-speed steel roll is then discharged from the furnace with slag, and pretreated with a composite material of Re and carbon powder. It is particularly important to note that the outer layer of molten steel for high-speed rolls contains over 12% total alloys such as Cr, Mo, and V. Once the molten steel surface is exposed, it is highly susceptible to oxidation. Therefore, the outer layer of molten steel for high-speed rolls must be discharged with protective slag, and the entire process must be performed using a sealed bottom ladle.

[0029] Special attention should be paid to the aluminum content in easily oxidized alloy materials, which should be controlled below 1.0 wt%. If the aluminum content in easily oxidized alloy materials exceeds the limit of 1.0 wt%, it will precipitate in the form of aluminum oxide and remain at the joint during the solidification of the outer layer of high-speed steel, affecting the bonding quality.

[0030] The best solution for controlling foreign non-metallic oxides at the roll bonding layer is to ensure that the casting ladle is clean, free of slag on the ladle wall, and that the refractory material at the ladle opening is not prone to falling off during casting. For the quality control of the centrifugal roll end caps, use unshaped refractory materials for tamping to prevent conventional end cap materials from becoming brittle, falling off, or shedding sand at high temperatures. The outer and middle layers of the roll molten steel casting system should be designed as a closed casting system, constructed with high-alumina refractory shaped eye bricks.

[0031] The centrifugal end caps of the roll production are shaped using monolithic refractory materials, and the closed casting system is constructed using molded bricks. The casting ladle is constructed using high-alumina bricks, and the ladle opening is also tied with monolithic refractory materials.

[0032] Achieving a high-quality metallurgical bond between the inner and outer layers of high-speed steel rolls requires two conditions: kinetic and thermodynamic conditions. Strict control of the metallurgical bond quality of high-speed steel rolls should focus on the pouring temperature and pouring interval (three temperatures and three times) of the molten iron for the outer, middle, and core layers.

[0033] The present invention controls the interval time of the middle layer pouring of high-speed steel rolls: the middle layer of molten steel is poured 4-18 minutes after the outer layer of molten steel is poured.

[0034] To control the metallurgical bonding quality between the middle layer and core layer of high-speed steel rolls, the following principles should be followed: minimize roll cooling and rotation time while preventing spillage, and ensure rapid core filling. The core filling temperature should be selected based on the middle layer material, appropriately increasing the pouring temperature while effectively preventing the penetration of the middle layer alloy into the core layer molten iron. Fast pouring speeds result in strong scouring of the "middle-core" interface by the core layer molten iron, creating favorable kinetic conditions. High-temperature core filling provides high thermodynamic conditions, facilitating the melting of the middle layer material. This operational control ensures a high-quality metallurgical bonding of the composite layer in the high-speed steel roll.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] This invention utilizes oxidation-protected smelting of the outer layer of molten steel in high-speed steel rolls and employs a slag-aggregating process to significantly control and reduce oxidation of the outer layer of molten iron, thereby improving the purity of the molten steel and eliminating the source of point defects in the roll bonding layer. By controlling the aluminum content in easily oxidized alloying elements and pre-treating the molten steel with Re and carbon powder composite materials during tapping, the precipitation of metallic and non-metallic oxides in the roll bonding layer can be effectively eliminated. Slag must be thoroughly removed during casting; the ladle must be clean, with no slag adhering to the ladle walls and minimal refractory material detachment at the ladle opening; quality control of the centrifugal roll end caps is achieved by using unshaped refractory materials for molding, preventing conventional end cap materials from becoming brittle, detaching, or shedding sand at high temperatures; the outer and middle layers of molten steel casting system are designed as a closed system, constructed using high-alumina refractory shaped eye bricks. By employing a bottom-blown ladle and a closed-loop casting system, and controlling the casting temperature and casting interval parameters of the outer, middle, and core layers of molten iron, the metallurgical bonding quality of high-speed steel rolls can be effectively improved and enhanced. Attached Figure Description

[0037] Figure 1 This is a diagram showing the precipitation of foreign matter on the free surface of the rolls when the easily oxidized alloy material used has an excessive aluminum content.

[0038] Figure 2 The graph shows the foreign matter precipitation on the free surface of the rolls when the easily oxidized alloy material used is stopped, provided that the aluminum content does not exceed the standard.

[0039] Figure 3 This is a photograph of the actual precipitated oxidized foreign matter.

[0040] Figure 4 This is a cross-sectional morphology diagram of the precipitated oxide foreign matter. Detailed Implementation

[0041] The implementation of the present invention will be further described below with reference to specific embodiments:

[0042] The present invention provides a method for controlling quality defects in the bonding layer of high-speed steel centrifugal composite rolls. This method is achieved by actively promoting the "three temperatures and three times" control concept in steel smelting anti-oxidation operations, purification casting systems, and roll casting.

[0043] A method for controlling quality defects in the bonding layer of high-speed steel centrifugal composite rolls includes the following:

[0044] 1. Preparation of outer and middle layers of molten steel for high-speed steel rolls

[0045] 1) The outer layer of molten steel for high-speed steel rolls uses raw materials with low sulfur content for batching and smelting to avoid desulfurization operations during the smelting process due to the high sulfur content of the outer layer of molten steel. For the outer and middle layers of high-speed steel rolls, priority should be given to using clean, unoxidized, impurity-free, and low-sulfur materials. The furnace charge should be clean with few impurities and low sulfur content to prevent desulfurization operations due to high sulfur content in the outer layer of molten steel for high-speed steel rolls. Practice has shown that when the sulfur content of the outer layer of high-speed steel is controlled at <0.018%, desulfurization operations can be eliminated.

[0046] 2) The outer layer of high-speed steel rolls is made of melted steel raw materials. Except for easily oxidized chemical components, all other alloy components are adjusted to meet the process requirements. The aluminum content in the alloy raw materials with easily oxidized chemical components is controlled below 1.0 wt%.

[0047] 3) The outer layer of molten steel for high-speed steel is heated to 1500-1580℃ and then transferred entirely from the smelting furnace into the ladle. The thinning agent should be evenly placed at the bottom of the ladle beforehand for thinning. The amount of thinning agent added is 0.20wt% to 1.0wt% of the total amount of molten steel discharged from the furnace.

[0048] 4) After the slag thinning operation is completed, skim off the floating slag from the surface of the molten steel and then use a slag-forming agent to form slag. The amount of slag-forming agent added should be enough to completely cover the surface of the molten steel;

[0049] 5) Adjusting the easily oxidizable chemical composition by returning molten steel to the furnace: Add 10wt% to 40wt% of preheated alloy material with easily oxidizable chemical composition to the bottom of the furnace in advance. After removing the slag material from the surface of the molten steel, quickly return the outer layer of high-speed steel to the furnace and add the remaining preheated alloy material with easily oxidizable chemical composition to the surface of the molten steel.

[0050] 6) Electricity is supplied for smelting, and new slag is made by adding crushed glass (the amount of crushed glass added should be enough to completely cover the surface of the molten steel).

[0051] 7) After all the easily oxidized alloy materials have been melted, heat the molten steel to 1490-1600℃ and let it stand for 30-60 minutes with slag before being taken out of the furnace.

[0052] 8) When the molten steel exits the outer layer of the high-speed rolls, it is pretreated with Re and carbon powder. The total amount of Re and carbon powder added is 0.20wt% to 0.50wt% of the total molten steel. Aluminum ingot deoxidation is eliminated. The entire process is done with a closed bottom ladle.

[0053] 9) For the middle layer of molten steel in high-speed steel rolls, ordinary carbon steel and rust-free scrap steel should be strictly selected for batching. All kinds of alloy rusted scrap steel are strictly prohibited from use.

[0054] 10) The smelting and tapping of the middle layer of high-speed steel rolls shall be carried out in accordance with the conventional graphite steel smelting process.

[0055] 2. Casting of molten steel for the outer and middle layers of high-speed steel rolls

[0056] 1) Argon blowing should be initiated immediately after the outer layer of molten steel for high-speed steel rolls exits the furnace. Argon blowing should be stopped when the molten steel reaches the product's process pouring temperature, and pouring can then proceed. The pouring temperature for the outer layer of molten steel for high-speed steel rolls is 1400–1500℃.

[0057] 2) For the outer layer of molten steel for high-speed steel pouring, slag removal is performed before the molten steel reaches the product pouring process temperature. Glass rock wool is used for slag blocking during pouring.

[0058] 3) Control of the pouring interval for the middle layer of high-speed steel rolls: The middle layer of molten steel should be poured 4–18 minutes after the outer layer of molten steel is poured. The pouring temperature for the middle layer of molten steel in high-speed steel rolls is 1480–1560℃.

[0059] 3. Preparation of high-speed steel roll production molding and gating system

[0060] 1) Centrifugal cold-formed end caps for high-speed steel roll production are pre-formed using monolithic refractory materials; the monolithic refractory materials are mixed with water and must be mixed using a sand mixer; after the end caps have solidified naturally, they are removed from the mold, cured for 30 hours, and then dried in the kiln.

[0061] 2) End caps made of unshaped refractory materials shall not be coated with any paint when put into use.

[0062] 3) Whether casting the outer or middle layer of high-speed steel, the casting channel through which the molten steel flows must be a closed casting system, constructed with high-grade refractory bricks. No refractory coating is permitted on the closed casting system.

[0063] 4) The outer layer molten steel ladle for high-speed steel rolls is a special ladle with bottom-leaking argon blowing; the middle layer molten steel ladle is a regular ladle. All ladles used in production are lined with high-alumina bricks, and the ladle opening is also secured with monolithic refractory material.

[0064] 4. Three-temperature and three-time control of high-speed steel roll casting

[0065] The so-called "three temperatures and three times" in high-speed steel roll casting refers to the casting temperatures of the outer layer, middle layer, and core layer of molten steel, the interval between casting the middle layer of molten steel, the time for the outer and middle layers of molten steel to cool, solidify, and rotate in the machine, and the control time for roll core filling. Any three-layer composite casting of a roll will result in poor roll bonding and scrap if the control of the three temperatures and three times is off.

[0066] Roll core filling speed and temperature control: To prevent spillage, stop roll cooling and quickly close the filling box; the roll core filling temperature should be selected based on the roll's middle layer material, aiming to maximize the pouring temperature while preventing the alloy of the middle layer material from penetrating into the core layer molten iron. Specific operations are as follows:

[0067] 1) Control of the interval time for pouring the middle layer of high-speed steel rolls: After the outer layer of molten steel is poured, the middle layer of molten steel is poured 4 to 18 minutes later; the middle layer of high-speed steel is filled quickly.

[0068] 2) The pouring of molten steel in the outer and middle layers of high-speed steel rolls must follow the principle of "fast filling, stable pouring, and slow slag removal".

[0069] 3) On the premise of ensuring that the outer and middle layers of the high-speed steel rolls cool and solidify and that no molten steel drips when the machine stops, terminate the roll cooling.

[0070] 4) Clean the residue at the port, stand the rolls and close the box, strictly control the roll tooling box closing time to <10min, control the roll core filling temperature to 1380~1460℃, and control the core filling speed to 40~100kg / s.

[0071] 5) The slow casting speed and low casting temperature of the roll core filler are not conducive to the metallurgical bonding between the outer middle layer and the core layer of the roll. To ensure the metallurgical bonding quality of the composite roll, the thermodynamic and kinetic conditions for the casting of the roll core filler must be sufficient.

[0072] 5. Inspection of high-speed steel rolls

[0073] 1) If a Φ2 point defect exists within the working layer of a high-speed steel roll, it indicates that the deoxidation and slag removal operations of the outer layer of molten steel during the high-speed steel roll smelting process are substandard. Using the high-speed steel roll outer layer molten steel preparation method described in this case, not a single case of a Φ2 point defect was found within the working layer of the roll.

[0074] 2) The timing of pouring molten steel into the middle layer of high-speed steel rolls is very important. The final standard is that the outer-middle bonding layer is free of defects and the actual thickness of the working layer of the roll meets the product process design.

[0075] 3) When the intermediate transition layer of the roll is thick, it indicates that the cooling and rotation time of the molten steel in the "outer-middle" layer of the roll is long and the core filling temperature is low. If there are multiple point defects <Φ5+4 at the junction of the intermediate transition layer and the core layer of the roll and there is no bottom wave attenuation, it indicates that the core filling time of the roll is delayed, which can be solved by increasing the pouring temperature of the molten iron for the core filling.

[0076] 6. Production Practice

[0077] This document presents a case study of a process simulation experiment for a high-speed steel roll of a certain specification. Experimental Examples 1 and 2 are comparative examples, while Examples 1 and 2 are embodiments of the present invention. The steel smelting process parameters for the case studies are shown in Table 1, and the steel casting process parameters for the case studies are shown in Table 2.

[0078] Table 1:

[0079]

[0080] Table 2:

[0081]

[0082] 7. The results of production practice are as follows:

[0083] 1) This invention has been successfully applied in industrial production. The overall quality pass rate of high-speed steel rolls of a certain roll manufacturing plant has steadily improved, and the quality pass rate of high-speed steel products has reached 100% for several consecutive months.

[0084] 2) The working layer of the roll was inspected with a 4M probe and no Φ2 point defects were found. The joint layer of the roll was inspected with an ultrasonic flaw detector using a 2M probe and no Φ5 point defects were found in the transition layer and joint layer of the roll.

[0085] 3) The aluminum content of the easily oxidized alloy raw materials used in production is effectively controlled below 1.0 wt%. After casting the outer middle layer of the high-speed steel rolls and stopping the machine, no oxide foreign matter precipitates are observed. For oxide precipitates, see [link to relevant documentation]. Figure 3 , Figure 4 Comparison of surface quality of rolls at shutdown, see Figure 1 and Figure 2 ).

[0086] 4) The metallurgical smelting operation of the high-alloy material outer layer of high-speed steel rolls effectively avoids desulfurization, anti-oxidation and slag thinning and cleaning operations, fundamentally purifying the internal quality of the molten steel in the outer layer of high-speed steel.

[0087] 5) The casting system is sealed with cast end caps and molded bricks, which eliminates sand falling from the end caps and keeps the casting system clean.

[0088] 6) Roll casting control method: implement "fast filling, stable casting, slow slag blocking" to effectively control the component segregation and slag blocking effect of high-speed steel and high alloy steel molten centrifugal forming.

[0089] 7) Implementing the "three temperatures and three times" casting parameter control concept is the key to obtaining the roll bonding layer without equivalent quality defects.

[0090] 8) Regarding the Φ5 point-like equivalent defects found in the roll bonding layer, dissection analysis revealed that all defects were metal oxides and non-metal oxides. Strict control over the high-speed steel roll bonding layer to eliminate point-like quality defects ensures the safe use of the high-speed steel rolls on the mill, preventing delamination and peeling.

Claims

1. A method for controlling quality defects in the bonding layer of a high-speed steel centrifugal composite roll, characterized in that, Includes the following: 1) Preparation of the outer layer of molten steel for high-speed steel rolls: a) The outer layer of steel raw material for high-speed steel rolls is melted and cleaned. Except for the easily oxidized chemical components, all other alloy components are adjusted to meet the process requirements. b) After the outer layer of high-speed steel is heated and superheated, it is completely transferred from the smelting furnace into the ladle. The thinning agent should be evenly placed at the bottom of the ladle beforehand to carry out the thinning operation; the amount of thinning agent added is 0.20wt% to 1.0wt% of the total amount of molten steel discharged from the furnace. c) After the slag thinning operation is completed, remove the floating slag from the surface of the molten steel and use a slag-aggregating agent to aggregate the slag. The amount of slag-aggregating agent added should be enough to completely cover the surface of the molten steel. d) Adjusting the easily oxidizable chemical composition by returning molten steel to the furnace: Add some preheated alloy materials with easily oxidizable chemical composition to the bottom of the furnace, remove the slag material from the surface of the molten steel, quickly return the outer layer of high-speed steel to the furnace, and add the remaining preheated alloy materials with easily oxidizable chemical composition to the surface of the molten steel. e) When the outer layer of molten steel from the high-speed steel roll is discharged from the furnace, the molten steel is pretreated with Re and carbon powder. The total amount of Re and carbon powder added is 0.20wt% to 0.50wt% of the total amount of molten steel, and aluminum cake deoxidation is eliminated. f) The pouring temperature of the outer layer of molten steel for high-speed steel rolls is 1400–1500℃; 2) Control of the pouring temperature and pouring interval of molten steel in the middle layer of high-speed steel rolls: a) The pouring temperature of molten steel in the middle layer of high-speed steel rolls is 1480~1560℃; b) Control of the interval time for pouring the middle layer of high-speed steel rolls: The middle layer of molten steel should be poured 4 to 18 minutes after the outer layer of molten steel is poured. 3) Control of cooling time for the outer and middle layers of molten steel in high-speed steel rolls: The roll cooling is terminated on the premise that no molten steel drips when the centrifuge is reduced in speed and stopped. 4) Control of roll core filling speed and temperature: After the roll cooling is stopped, the core filling box is quickly closed; the roll core filling temperature is selected based on the roll middle layer material. Under the premise of avoiding the penetration of the roll middle layer material alloy into the core layer molten iron during roll core filling, the core layer pouring temperature should be increased as much as possible.

2. The method for controlling quality defects in the bonding layer of a high-speed steel centrifugal composite roll according to claim 1, characterized in that, The outer layer of molten steel for the high-speed steel roll is produced using raw materials with low sulfur content, thus avoiding desulfurization operations during the smelting process.

3. The method for controlling quality defects in the bonding layer of a high-speed steel centrifugal composite roll according to claim 2, characterized in that, The sulfur content of the molten steel in the outer layer of the high-speed steel roll is controlled to be <0.018wt%.

4. The method for controlling quality defects in the bonding layer of a high-speed steel centrifugal composite roll according to claim 1, characterized in that, In steps 1)-b), the molten steel is heated to 1500-1580°C and then removed from the furnace for slag thinning.

5. The method for controlling quality defects in the bonding layer of a high-speed steel centrifugal composite roll according to claim 1, characterized in that, In steps 1)-d), 10wt% to 40wt% of preheated alloy material with easily oxidizable chemical composition is added to the bottom of the furnace beforehand.

6. The method for controlling quality defects in the bonding layer of a high-speed steel centrifugal composite roll according to claim 1, characterized in that, The aluminum content in the alloy raw material with the easily oxidized chemical composition is controlled to be below 1.0 wt%.

7. The method for controlling quality defects in the bonding layer of a high-speed steel centrifugal composite roll according to claim 1, characterized in that, In steps 1)-d), after all the easily oxidizable chemical alloy materials have been melted, the molten steel is heated to 1490-1600℃ and left to stand for 30-60 minutes with slag before being tapped out of the furnace.

8. The method for controlling quality defects in the bonding layer of a high-speed steel centrifugal composite roll according to claim 1, characterized in that, The carbon content of the molten steel in the middle layer of the high-speed steel roll is <2.0wt%; the molten steel in the middle layer of the high-speed steel roll is made from rust-free ordinary carbon scrap steel.

9. The method for controlling quality defects in the bonding layer of a high-speed steel centrifugal composite roll according to claim 1, characterized in that, In step 4), the roll tooling box closing time is <10min, the roll core filling temperature is controlled at 1380~1460℃, and the core filling speed is controlled at 40~100kg / s.

10. The method for controlling quality defects in the bonding layer of a high-speed steel centrifugal composite roll according to claim 1, characterized in that, The centrifugal end caps of the roll production are shaped using monolithic refractory materials, and the closed casting system is constructed using molded bricks. The casting ladle is constructed using high-alumina bricks, and the ladle opening is also tied with monolithic refractory materials.

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