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CN-122007823-A - Composite manufacturing method of Cr18 high-chromium cast iron medium-speed grinding roller

CN122007823ACN 122007823 ACN122007823 ACN 122007823ACN-122007823-A

Abstract

The invention discloses a composite manufacturing method of a Cr18 high-chromium cast iron medium-speed grinding roller, which comprises the steps of grinding roller blank casting, rough machining, detection before surfacing, preparation before surfacing, surfacing operation, surfacing end, quality detection and post-welding machining; the invention adopts the open arc overlaying method to carry out alloy overlaying on the surface of the grinding roller made of high-chromium wear-resistant steel, high-chromium cast iron and other materials, avoids the direct abrasion of cast iron parent metal in the use process of the grinding roller, and welds an alloy wear-resistant layer with the thickness of 30-40mm, thereby greatly improving the wear resistance of the grinding roller and prolonging the service life to 12-18 months.

Inventors

  • JING CHAO
  • YANG YANCHENG
  • LI JIANPING
  • JIN YONGQI

Assignees

  • 甘肃酒钢集团西部重工股份有限公司

Dates

Publication Date
20260512
Application Date
20260331

Claims (5)

  1. 1.A composite manufacturing method of a Cr18 high-chromium cast iron medium-speed grinding roller is characterized by comprising the following steps: s1, casting a grinding roller blank: the grinding roller blank comprises 2.5-2.8% of C, 18-20% of Cr, 0.8-1.2% of Ni, 0.4-0.6% of Mo, less than or equal to 0.03% of P and less than or equal to 0.03% of S, wherein the outer edge of the blank is reserved with single-side 30-40mm surfacing quantity, and the upper end face and the lower end face are reserved with single-side 5mm processing quantity; s2, rough machining: Aligning the grinding roller blank prepared in the step S1 on a vertical lathe, and processing the upper end surface and the lower end surface of the grinding roller blank to the height dimension of a finished roller sleeve to obtain a roller sleeve parent metal; S3, detection before surfacing: Detecting that the chemical composition of the parent metal of the roller sleeve meets the requirements; Detecting carbide tissue distribution and other metallographic structure conditions in the parent material of the roller sleeve; Ultrasonic flaw detection and surface penetration flaw detection are carried out on the surfacing position of the parent material of the roller sleeve, and casting defects such as shrinkage porosity, slag inclusion, cracks and the like which affect the surfacing quality are confirmed on the internal tissues and the surfaces; uniformly polishing 8-10 hardness detection points on one circle of a surfacing surface of a parent metal of the roll sleeve, and detecting whether the hardness of the surfacing surface is uniform or not and whether the hardness drop is less than or equal to 5HRC or not; S4, preparation before surfacing: The positioner is adjusted to a horizontal position, the parent metal of the roller sleeve which is qualified in S3 detection is fixed on a workbench of the positioner, the angle of the workbench of the positioner is adjusted to 75-80 degrees from the horizontal position, an air outlet of a compressed air hose is aligned with the 4 o 'clock direction of the surfacing surface of the roller sleeve, and a spray water cooling device is aligned with the 8 o' clock direction of the surfacing surface of the roller sleeve; s5, surfacing operation: the welding material adopts a wear-resistant flux-cored wire; The first 2 times of surfacing, namely, the current is 280A-330A, the voltage is 28-30V, the wire feeding speed is 2.0-2.4m/min, the dry extension length is 20-30mm, and the rotating speed of a positioner is 4-5min/r; Filling and overlaying, namely, 300A-380A of current, 30-35V of voltage, 2.4-3.0m/min of wire feeding speed, 20-30mm of dry extension length and 3.5-4.5min/r of rotating speed of a positioner; Facing surfacing, namely, current is 280A-330A, voltage is 28-30V, wire feeding speed is 2.0-2.4m/min, dry extension length is 20-30mm, and rotating speed of a positioner is 4-5min/r; detecting by using a template in the overlaying process, and stopping overlaying until the size of the template is reached; s6, finishing surfacing: The positioner continues to rotate, the roller sleeve is cooled by adopting an air cooling and spray cooling mode, and when the temperature of the roller sleeve is reduced to the room temperature, the compressed air and spray cooling device is firstly closed, and then the rotation of the positioner is stopped; s7, quality detection: polishing 6-8 points on the surfacing surface of the roller sleeve for hardness detection, wherein the hardness is more than or equal to HRC 60; s8, post-welding processing: And hoisting and transporting the roller sleeve, and processing an inner hole assembly surface to the required size of the finished grinding roller after aligning on the vertical lathe.
  2. 2. The method for manufacturing a Cr18 high-chromium cast iron medium-speed grinding roller according to claim 1, wherein the welding material in S5 is LZ603 bright-arc alloy welding wire, and the diameter of the welding wire is phi 2.8mm.
  3. 3. The composite manufacturing method of the Cr18 high-chromium cast iron medium-speed grinding roller is characterized in that in S5, the temperature of the roller sleeve is detected every half hour in the surfacing operation, when the temperature is more than or equal to 100 ℃, the surfacing operation is stopped, the positioner continues to rotate at the speed of 4-5min/r, the roller sleeve is cooled by adopting an air cooling and spray cooling mode, the surfacing can be continued when the temperature is reduced to 50+/-2 ℃, and when the temperature of the surfacing surface is more than 50 ℃, the cooling water in the inner cavity of the roller sleeve is strictly forbidden to be replaced.
  4. 4. The method for manufacturing a Cr18 high-chromium cast iron medium-speed grinding roller according to claim 3, wherein the first 2 passes of build-up welding in S5 uses air-cooling, and the filling build-up welding uses air-cooling and spray cooling.
  5. 5. The method for manufacturing a Cr18 high-chromium cast iron medium-speed grinding roller according to claim 4, wherein the rotational speed of the positioner in step S6 is 4 to 5min/r.

Description

Composite manufacturing method of Cr18 high-chromium cast iron medium-speed grinding roller Technical Field The invention belongs to the technical field of medium-speed grinding rollers, and particularly relates to a composite manufacturing method of a Cr18 high-chromium cast iron medium-speed grinding roller. Background In production, a medium-speed grinding roll (hereinafter referred to as "grinding roll") grinds raw coal falling from the central coal-falling pipe. The grinding roller operates at high temperature, so that the grinding roller bears larger grinding pressure and impact force caused by raw coal, and the effective grinding area of the grinding roller is reduced along with continuous impact and abrasion of raw materials on the grinding roller, so that wavy grains are formed, and the equipment efficiency is drastically reduced. When the grinding roller wears to the scrapped size, only a new grinding roller can be replaced. As the grinding roller is generally made of high-chromium wear-resistant steel, high-chromium cast iron and other materials, the grinding roller has better wear resistance, and needs to be repaired by online or offline surfacing after being generally used for 4-5 months, the manufacturing cost is high, the replacement procedure is complex, the period is long, and the cost is higher. Disclosure of Invention The invention aims to provide a composite manufacturing method of a Cr18 high-chromium cast iron medium-speed grinding roller, which aims to solve the problems. In order to achieve the above purpose, the invention adopts the following technical scheme: A composite manufacturing method of a Cr18 high-chromium cast iron medium-speed grinding roller comprises the following steps: s1, casting a grinding roller blank: the grinding roller blank comprises 2.5-2.8% of C, 18-20% of Cr, 0.8-1.2% of Ni, 0.4-0.6% of Mo, less than or equal to 0.03% of P and less than or equal to 0.03% of S, wherein the outer edge of the blank is reserved with single-side 30-40mm surfacing quantity, and the upper end face and the lower end face are reserved with single-side 5mm processing quantity; s2, rough machining: Aligning the grinding roller blank prepared in the step S1 on a vertical lathe, and processing the upper end surface and the lower end surface of the grinding roller blank to the height dimension of a finished roller sleeve to obtain a roller sleeve parent metal; S3, detection before surfacing: Detecting that the chemical composition of the parent metal of the roller sleeve meets the requirements; Detecting carbide tissue distribution and other metallographic structure conditions in the parent material of the roller sleeve; Ultrasonic flaw detection and surface penetration flaw detection are carried out on the surfacing position of the parent material of the roller sleeve, and casting defects such as shrinkage porosity, slag inclusion, cracks and the like which affect the surfacing quality are confirmed on the internal tissues and the surfaces; uniformly polishing 8-10 hardness detection points on one circle of a surfacing surface of a parent metal of the roll sleeve, and detecting whether the hardness of the surfacing surface is uniform or not and whether the hardness drop is less than or equal to 5HRC or not; S4, preparation before surfacing: The positioner is adjusted to a horizontal position, the parent metal of the roller sleeve which is qualified in S3 detection is fixed on a workbench of the positioner, the angle of the workbench of the positioner is adjusted to 75-80 degrees from the horizontal position, an air outlet of a compressed air hose is aligned with the 4 o 'clock direction of the surfacing surface of the roller sleeve, and a spray water cooling device is aligned with the 8 o' clock direction of the surfacing surface of the roller sleeve; s5, surfacing operation: the welding material adopts a wear-resistant flux-cored wire; The first 2 times of surfacing, namely, the current is 280A-330A, the voltage is 28-30V, the wire feeding speed is 2.0-2.4m/min, the dry extension length is 20-30mm, and the rotating speed of a positioner is 4-5min/r; Filling and overlaying, namely, 300A-380A of current, 30-35V of voltage, 2.4-3.0m/min of wire feeding speed, 20-30mm of dry extension length and 3.5-4.5min/r of rotating speed of a positioner; Facing surfacing, namely, current is 280A-330A, voltage is 28-30V, wire feeding speed is 2.0-2.4m/min, dry extension length is 20-30mm, and rotating speed of a positioner is 4-5min/r; detecting by using a template in the overlaying process, and stopping overlaying until the size of the template is reached; s6, finishing surfacing: The positioner continues to rotate, the roller sleeve is cooled by adopting an air cooling and spray cooling mode, and when the temperature of the roller sleeve is reduced to the room temperature, the compressed air and spray cooling device is firstly closed, and then the rotation of the positioner is stopped; s7, quality de