CN113584548A - Composite plating process for chromium-base ceramic of piston ring - Google Patents

Composite plating process for chromium-base ceramic of piston ring Download PDF

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Publication number
CN113584548A
CN113584548A CN202110889456.8A CN202110889456A CN113584548A CN 113584548 A CN113584548 A CN 113584548A CN 202110889456 A CN202110889456 A CN 202110889456A CN 113584548 A CN113584548 A CN 113584548A
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Prior art keywords
piston ring
ring
chromium
coating
piston
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Inventor
邓章礼
王四春
张立国
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Changsha Zhengyuan Power Technology Co ltd
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Changsha Zhengyuan Power Technology Co ltd
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D7/00—Electroplating characterised by the article coated
    • C25D7/04—Tubes; Rings; Hollow bodies
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D17/00—Constructional parts, or assemblies thereof, of cells for electrolytic coating
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D17/00—Constructional parts, or assemblies thereof, of cells for electrolytic coating
    • C25D17/06—Suspending or supporting devices for articles to be coated
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/34—Pretreatment of metallic surfaces to be electroplated
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/48—After-treatment of electroplated surfaces
    • C25D5/50—After-treatment of electroplated surfaces by heat-treatment
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/48—After-treatment of electroplated surfaces
    • C25D5/52—After-treatment of electroplated surfaces by brightening or burnishing
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D9/00—Electrolytic coating other than with metals
    • C25D9/04—Electrolytic coating other than with metals with inorganic materials

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Electroplating Methods And Accessories (AREA)

Abstract

The invention relates to the technical field of piston ring coatings, in particular to a chromium-based ceramic composite coating process for a piston ring, which aims to solve the problem that the traditional piston ring is easy to cause cylinder scuffing and specifically comprises eight steps. The chromium-based ceramic composite coating contains 2-6 vol% of ceramic particles (Al)2O3) 40-100 micro cracks/mm, high coating hardness of 800-1200HV0.1Micro-crackingThe oil storage performance is good, the lubricating condition is improved, the friction loss is reduced, the wear resistance is higher, the service life of the piston ring is more than 5 times that of a common chromium-plated piston ring, and the problems that the traditional piston ring is easy to wear and tear a cylinder are effectively solved.

Description

Composite plating process for chromium-base ceramic of piston ring
Technical Field
The invention relates to the technical field of piston ring plating layers, in particular to a chromium-based ceramic composite plating process for a piston ring.
Background
The piston ring is a metal elastic ring with large outward expansion deformation, which is assembled in a ring groove with a section corresponding to the section, the piston ring moves in a reciprocating and rotating way, seals are formed between the outer circular surface of the ring and a cylinder and between the ring and one side surface of the ring groove by the pressure difference of gas or liquid, in order to improve the service performance of the piston ring, chrome plating is generally needed to be carried out on the surface of the piston ring, the existing chrome plating process uses sulfate radical as a catalyst, and the basic components of the plating solution are chromic anhydride and sulfuric acid, CrO 3: h2SO4 ═ 100: 1, using a workpiece (piston ring) as a cathode, using lead alloy as an anode, and plating a thin hard chromium layer on the outer circular surface of the piston ring by electrochemical deposition, wherein:
and (3) cathode reaction: cr (chromium) component2O7 2-+14H++6e→2Cr3++7H2O
2H++2e→H2↑
HCrO4-+6e+3H+→Cr+4OH-
And (3) anode reaction: 2H2O-4e→O2+4H+
2Cr3++7H2O-6e→Cr2O7 2-+14H+
Pb+7H2O-4e→PbO2+4H
With the continuous improvement of the emission level of an engine, the traditional chromium-plated piston ring is easy to generate a cylinder scuffing phenomenon under the working environment with high heat load and low engine oil consumption. Accordingly, those skilled in the art have provided a chromium-based ceramic composite plating process for piston rings to solve the problems set forth in the background art described above.
Disclosure of Invention
The invention aims to provide a chromium-based ceramic composite plating process for a piston ring, which aims to solve the problems in the background technology.
In order to achieve the purpose, the invention provides the following technical scheme: the composite chromium-based ceramic plating process for piston rings comprises the following steps:
step 1: clamping, sealing and cleaning mouth
S1: drawing the corresponding clamping fixture;
s2: placing the demagnetized piston ring on a special angle iron to align the opening of the piston ring;
s3: horizontally arranging a piston ring with an opening aligned with the height equal to the clamping length of the shaft on a mandrel in the semicircular tile;
s4: coating varnish into an opening gap of a piston ring by using a special tool, staggering the opening of the piston ring by about 90 degrees, starting a pneumatic valve, sleeving a corresponding nut on a mandrel, and tightening by using a wrench;
s5: moving the shaft with the piston ring on the support, brushing varnish on the surface of the piston ring by using an iron brush, and wiping the opening part by dipping cotton yarn in acetone within a range of nearly 45 degrees to wipe off redundant varnish as much as possible;
step 2: examination of
A1, checking and clamping: checking that the closed gap of the piston ring is within the range of 0.15-0.25mm, the excircle surface is flat after clamping, the condition of unevenness is not allowed to exist, the ring is not allowed to be broken, otherwise, the clamping is removed and the re-assembly is carried out, and the clamped piston ring is placed at the next stop point after being qualified;
a2, checking and sealing: visually checking whether all piston rings are sealed and whether the piston ring with a large opening gap is solid or not, and if not, sealing again;
a3, inspection and mouth cleaning: visually checking whether all the residual varnish of the piston ring is brushed cleanly or not, wherein the residual varnish comprises an outer circular surface, a chamfer and an opening, and placing the piston ring at the next stop point after the residual varnish is qualified;
and step 3: sand blasting and rinsing
B1: picking up a piston ring to be processed from a corresponding stop point;
b2: starting the air pressure to start the sand blasting machine to idle for a stroke, checking whether the air pressure is normal or not, and filling an equipment daily check table;
b3: the granularity of the sand for sand blasting is W63;
b4: installing a conductive rod and a plastic upper protective sleeve, screwing the copper conductive rod by a wrench, and putting the copper conductive rod into a sand blasting machine;
b5: turning on a power switch, automatically operating the sand blasting machine to blast sand for one stroke, and annularly blasting each cylinder of piston for two strokes;
b6: after the sand blasting is finished, the piston ring is lifted out of the sand blasting machine, and whether the ring body is completely blasted and the color is uniform and is in tile gray is visually observed;
b7: the piston ring after sand blasting is rinsed in a rinsing tank and then sprayed in a high-pressure water spraying tank to remove residual sand grains on the surface of the ring body and check whether the seal is intact;
b8: replacing the sand water in the sand blasting machine every week, wherein the proportion of the sand water is 15-20%;
and 4, step 4: electroplating of
C1: picking up the piston ring to be plated from the corresponding stop point;
c2: confirming the temperature of the bath solution: 60 +/-1 ℃;
c3: and (3) confirming the chemical components of the bath solution:
chromium trioxide: 200 to 280g/L
Sulfuric acid: 2.0 to 2.8g/L
Methanesulfonic acid: 1.5 to 1.8g/L
Anhydrous potassium fluoride: 5.6 to 6.0g/L
Basic lead carbonate: 0.5 to 1.5g/L
Alumina: 10 to 30g/L
Trivalent chromium ion: 1 to 8g/L
A positive ferric ion: less than or equal to 10g/L
C4: selecting an electroplating process number according to the machine type and filling a chromium plating procedure operation record table;
c5: the determination of the electroplating process number is set by a specially-assigned person according to a set basis;
c6: aligning the workpiece to a lower groove in the center of the cathode ring, preventing the workpiece from colliding with the cathode ring, and knocking the conductive copper disc by using a wood hammer or a lead bar after the cathode ring is contacted with the conductive copper disc so as to enable the conductive copper disc to be tightly contacted with the cathode ring;
c7: confirming the process number again, and pressing a start key;
c8: pressing a stop key to lift the workpiece out of the bath to flush residual bath;
c9: putting the workpiece into a cleaning and recycling tank, and cleaning and recycling a small part of residual plating solution to avoid environmental pollution and waste;
and 5: polishing and removing clamp after plating
D1: picking up a piston ring to be thrown from a corresponding stopping point;
d2: checking whether the polishing machine works normally;
d3: checking whether the abrasive belt meets the process requirements;
d4: placing the plated piston ring on a machine tool, starting a power supply, and automatically operating and polishing by a polishing machine for two strokes;
d5: and (3) polishing inspection: after polishing, the surface of the chromium plating layer is checked by naked eyes, and no obvious burr chromium tumor is confirmed;
d6: after the inspection is qualified, the clamp is removed and the cleaning is carried out;
step 6: dehydrogenation
F1: picking up a piston ring to be processed from a corresponding stop point;
f2: checking whether the temperature setting of the oven is 210 ℃ or not, and checking whether the air blowing effect of the oven is normal or not;
f3: the dehydrogenation temperature is 210 +/-10 ℃, the dehydrogenation time of the nodular cast iron piston ring is 4 hours +/-5 minutes, and the dehydrogenation time of the gray cast iron piston ring is 3 hours +/-5 minutes;
f4: the piston ring to be dehydrogenated is arranged in an oven, and the piston ring in the oven does not exceed 16 rods each time;
f5: closing the oven door, opening a power switch to remove hydrogen, keeping the temperature for a corresponding time after reaching the temperature, cutting off the power supply, and cooling in air to normal temperature;
f6: the piston ring in the oven is moved out of the oven, and is placed on a working table surface to be detected in order after demagnetization;
and 7: examination of
The appearance, magnetism, coating thickness, bonding strength, ceramic particle components, ceramic particle size, ceramic particle hardness, coating microcrack density and coating ceramic particle content are inspected to determine whether the process requirements are met;
and 8: sampling and checking
And (4) performing subsequent spot inspection on the qualified products in the step (7), and packaging and warehousing after the qualified products are qualified.
As a further aspect of the invention: the air pressure in B2 was: 5.5-6.5kgf/cm2。
As a further aspect of the invention: the data set in C5 are specifically as follows:
current density of upper and lower layers: 90 +/-5A/dm2Time 120-;
positive plating current density: 70 +/-5A/dm2Time 1000-;
composite plating current density: 70 +/-5A/dm2Time 700 and 750 seconds;
composite corrosion current density: 50 +/-5A/dm2Time is 70-78 seconds;
the number of plating cycles N is determined by the plating thickness.
As a further aspect of the invention: the process requirements of the abrasive belt in D3 are as follows: the granularity of the abrasive belt is 240#, and one abrasive belt is replaced when 10 cylinders are thrown.
As a further aspect of the invention: the process requirements in step 7 are as follows:
appearance:
a: the coating is not allowed to have bubbles, fall off, pockmarks, collapse openings, slag inclusion, no coating on the surface, no peeling, dovetail and fish scale stripes and no micro cracks visible to naked eyes;
b: the plating layer should not have serious chrome nodules, and the chrome nodules at local points should be less than or equal to 0.30 mm;
c: pinhole of the outer disc: the maximum size of the pinhole is less than or equal to 0.20 mm;
d: coating excircle edge: the edge of the excircle should not have minor saw-tooth shape and unevenness defects (including chrome nodules);
e: the boundary line of the joint surface of the ring land embedded with the piston ring and the plating layer is clear, and the plating layer is not allowed to exist on the surface of the ring land;
magnetism: the method is based on the condition of unobvious iron-absorbing ash;
coating thickness: performing according to relevant process requirements;
bonding strength: the coating should not separate from the substrate, fragments of the coating should not exceed half the thickness of the coating;
ceramic particle composition: aluminum oxide;
ceramic particle size: the diameter is 0.5-5 um;
hardness of ceramic particles: 2200-3000HV 0.025;
coating hardness: 800-1200HV0.1；
Plating layer microcrack density: 40-100 strips/mm;
the content of the ceramic particles of the plating layer is as follows: 2-6% (volume), 1.1-3.3% (weight), 0.6-1.7% (aluminum).
As a further aspect of the invention: the specific method in step 8 is as follows:
the appearance is checked by 100 percent by visual inspection;
sampling the thickness of the plating layer for detection: the gap of each non-embedded piston ring station is measured by a flow inspector by a gap ring, 1 piston ring is taken from each shift, the thickness of a coating is measured by a metallographic microscope, and the external grinding size of the embedded piston ring is accurate.
Bonding strength: detecting the bonding strength of 1 piston ring in each batch, detecting the nodular cast iron piston ring by a twisting method, performing visual inspection after the two opening surfaces are twisted by 90 degrees, and detecting the gray cast iron piston ring by a breaking method;
sampling and detecting the hardness and the density of microcracks of the plating layer: detecting the hardness and the density of microcracks of the plating layer by drawing 1 piston ring per shift;
ceramic particle content (gravimetric method): the weight of the piston ring before chromium stripping is G1, the weight of the piston ring after chromium stripping is G2, the weight of the coating is G1-G2, the ceramic particles after chromium stripping are filtered out, the ceramic particles are dried and weighed G3, the content of the ceramic particles is G3 x 100/G, and the detection is carried out for 1 time per month.
Compared with the prior art, the invention has the beneficial effects that: the chromium-based ceramic composite coating contains 2-6% (by volume) of ceramic particles (Al)2O3) 40-100 micro cracks/mm, high coating hardness of 800-1200HV0.1The micro-crack has good oil storage performance, improves the lubricating condition, reduces the friction loss, has higher wear resistance, has the service life more than 5 times that of the common chromium-plated piston ring, and effectively solves the problems that the traditional piston ring is easy to wear and easy to pullProblems with the cylinder.
Drawings
FIG. 1 is a schematic structural view of a chromium-based ceramic composite coating according to the present invention;
FIG. 2 is a surface topography of the chromium-based ceramic composite coating of the present invention;
FIG. 3 is a cross-sectional view of the chromium-based ceramic composite plating layer of the present invention.
FIG. 4 is a sample diagram of the hardness test of the plating layer in the test example of the chromium-based ceramic composite plating process of the present invention;
FIG. 5 is a graph showing the content of the ceramic particles in the chromium-based ceramic composite plating layer according to the present invention.
Detailed Description
Referring to fig. 1 to 3, in an embodiment of the present invention, a chromium-based ceramic composite plating process for a piston ring includes the following steps:
step 1: clamping, sealing and cleaning mouth
S1: drawing the corresponding clamping fixture;
s2: placing the demagnetized piston ring on a special angle iron to align the opening of the piston ring;
s3: horizontally arranging a piston ring with an opening aligned with the height equal to the clamping length of the shaft on a mandrel in the semicircular tile;
s4: coating varnish into an opening gap of a piston ring by using a special tool, staggering the opening of the piston ring by about 90 degrees, starting a pneumatic valve, sleeving a corresponding nut on a mandrel, and tightening by using a wrench;
s5: moving the shaft with the piston ring on the support, brushing varnish on the surface of the piston ring by using an iron brush, and wiping the opening part by dipping cotton yarn in acetone within a range of nearly 45 degrees to wipe off redundant varnish as much as possible;
step 2: examination of
A1, checking and clamping: checking that the closed gap of the piston ring is within the range of 0.15-0.25mm, the excircle surface is flat after clamping, the condition of unevenness is not allowed to exist, the ring is not allowed to be broken, otherwise, the clamping is removed and the re-assembly is carried out, and the clamped piston ring is placed at the next stop point after being qualified;
a2, checking and sealing: visually checking whether all piston rings are sealed and whether the piston ring with a large opening gap is solid or not, and if not, sealing again;
a3, inspection and mouth cleaning: visually checking whether all the residual varnish of the piston ring is brushed cleanly or not, wherein the residual varnish comprises an outer circular surface, a chamfer and an opening, and placing the piston ring at the next stop point after the residual varnish is qualified;
and step 3: sand blasting and rinsing
B1: picking up a piston ring to be processed from a corresponding stop point;
b2: starting the air pressure to start the sand blasting machine to idle for a stroke, checking whether the air pressure is normal or not, and filling an equipment daily check table;
b3: the granularity of the sand for sand blasting is W63;
b4: installing a conductive rod and a plastic upper protective sleeve, screwing the copper conductive rod by a wrench, and putting the copper conductive rod into a sand blasting machine;
b5: turning on a power switch, automatically operating the sand blasting machine to blast sand for one stroke, and annularly blasting each cylinder of piston for two strokes;
b6: after the sand blasting is finished, the piston ring is lifted out of the sand blasting machine, and whether the ring body is completely blasted and the color is uniform and is in tile gray is visually observed;
b7: the piston ring after sand blasting is rinsed in a rinsing tank and then sprayed in a high-pressure water spraying tank to remove residual sand grains on the surface of the ring body and check whether the seal is intact;
b8: replacing the sand water in the sand blasting machine every week, wherein the proportion of the sand water is 15-20%;
and 4, step 4: electroplating of
C1: picking up the piston ring to be plated from the corresponding stop point;
c2: confirming the temperature of the bath solution: 60 +/-1 ℃;
c3: and (3) confirming the chemical components of the bath solution:
chromium trioxide: 200 to 280g/L
Sulfuric acid: 2.0 to 2.8g/L
Methanesulfonic acid: 1.5 to 1.8g/L
Anhydrous potassium fluoride: 5.6 to 6.0g/L
Basic lead carbonate: 0.5 to 1.5g/L
Alumina: 10 to 30g/L
Trivalent chromium ion: 1 to 8g/L
A positive ferric ion: less than or equal to 10g/L
C4: selecting an electroplating process number according to the machine type and filling a chromium plating procedure operation record table;
c5: the determination of the electroplating process number is set by a specially-assigned person according to a set basis;
c6: aligning the workpiece to a lower groove in the center of the cathode ring, preventing the workpiece from colliding with the cathode ring, and knocking the conductive copper disc by using a wood hammer or a lead bar after the cathode ring is contacted with the conductive copper disc so as to enable the conductive copper disc to be tightly contacted with the cathode ring;
c7: confirming the process number again, and pressing a start key;
c8: pressing a stop key to lift the workpiece out of the bath to flush residual bath;
c9: putting the workpiece into a cleaning and recycling tank, and cleaning and recycling a small part of residual plating solution to avoid environmental pollution and waste;
and 5: polishing and removing clamp after plating
D1: picking up a piston ring to be thrown from a corresponding stopping point;
d2: checking whether the polishing machine works normally;
d3: checking whether the abrasive belt meets the process requirements;
d4: placing the plated piston ring on a machine tool, starting a power supply, and automatically operating and polishing by a polishing machine for two strokes;
d5: and (3) polishing inspection: after polishing, the surface of the chromium plating layer is checked by naked eyes, and no obvious burr chromium tumor is confirmed;
d6: after the inspection is qualified, the clamp is removed and the cleaning is carried out;
step 6: dehydrogenation
F1: picking up a piston ring to be processed from a corresponding stop point;
f2: checking whether the temperature setting of the oven is 210 ℃ or not, and checking whether the air blowing effect of the oven is normal or not;
f3: the dehydrogenation temperature is 210 +/-10 ℃, the dehydrogenation time of the nodular cast iron piston ring is 4 hours +/-5 minutes, and the dehydrogenation time of the gray cast iron piston ring is 3 hours +/-5 minutes;
f4: the piston ring to be dehydrogenated is arranged in an oven, and the piston ring in the oven does not exceed 16 rods each time;
f5: closing the oven door, opening a power switch to remove hydrogen, keeping the temperature for a corresponding time after reaching the temperature, cutting off the power supply, and cooling in air to normal temperature;
f6: the piston ring in the oven is moved out of the oven, and is placed on a working table surface to be detected in order after demagnetization;
and 7: examination of
The appearance, magnetism, coating thickness, bonding strength, ceramic particle components, ceramic particle size, ceramic particle hardness, coating microcrack density and coating ceramic particle content are inspected to determine whether the process requirements are met;
and 8: sampling and checking
And (4) performing subsequent spot inspection on the qualified products in the step (7), and packaging and warehousing after the qualified products are qualified.
Further, the air pressure in B2 is: 5.5-6.5kgf/cm2。
Further, the setting data in C5 are specifically as follows:
current density of upper and lower layers: 90 +/-5A/dm2Time 120-;
positive plating current density: 70 +/-5A/dm2Time 1000-;
composite plating current density: 70 +/-5A/dm2Time 700 and 750 seconds;
composite corrosion current density: 50 +/-5A/dm2Time is 70-78 seconds;
the number of plating cycles N is determined by the plating thickness.
Further, the process requirements of the sand belt in D3 are as follows: the granularity of the abrasive belt is 240#, and one abrasive belt is replaced when 10 cylinders are thrown.
Further, the process requirements in step 7 are as follows:
appearance:
a: the coating is not allowed to have bubbles, fall off, pockmarks, collapse openings, slag inclusion, no coating on the surface, no peeling, dovetail and fish scale stripes and no micro cracks visible to naked eyes;
b: the plating layer should not have serious chrome nodules, and the chrome nodules at local points should be less than or equal to 0.30 mm;
c: pinhole of the outer disc: the maximum size of the pinhole is less than or equal to 0.20 mm;
d: coating excircle edge: the edge of the excircle should not have minor saw-tooth shape and unevenness defects (including chrome nodules);
e: the boundary line of the joint surface of the ring land embedded with the piston ring and the plating layer is clear, and the plating layer is not allowed to exist on the surface of the ring land;
magnetism: the method is based on the condition of unobvious iron-absorbing ash;
coating thickness: performing according to relevant process requirements;
bonding strength: the coating should not separate from the substrate, fragments of the coating should not exceed half the thickness of the coating;
ceramic particle composition: aluminum oxide;
ceramic particle size: the diameter is 0.5-5 um;
hardness of ceramic particles: 2200-3000HV 0.025;
coating hardness: 800-1200HV0.1；
Plating layer microcrack density: 40-100 strips/mm;
the content of the ceramic particles of the plating layer is as follows: 2-6% (volume), 1.1-3.3% (weight), 0.6-1.7% (aluminum).
Further, the specific method in step 8 is as follows:
the appearance is checked by 100 percent by visual inspection;
sampling the thickness of the plating layer for detection: the gap of each non-embedded piston ring station is measured by a flow inspector by a gap ring, 1 piston ring is taken from each shift, the thickness of a coating is measured by a metallographic microscope, and the external grinding size of the embedded piston ring is accurate.
Bonding strength: detecting the bonding strength of 1 piston ring in each batch, detecting the nodular cast iron piston ring by a twisting method, performing visual inspection after the two opening surfaces are twisted by 90 degrees, and detecting the gray cast iron piston ring by a breaking method;
sampling and detecting the hardness and the density of microcracks of the plating layer: detecting the hardness and the density of microcracks of the plating layer by drawing 1 piston ring per shift;
ceramic particle content (gravimetric method): the weight of the piston ring before chromium stripping is G1, the weight of the piston ring after chromium stripping is G2, the weight of the coating is G1-G2, the ceramic particles after chromium stripping are filtered out, the ceramic particles are dried and weighed G3, the content of the ceramic particles is G3 x 100/G, and the detection is carried out for 1 time per month.
Examination example
Coating hardness test report
Figure RE-GDA0003288159860000101
Figure RE-GDA0003288159860000111
Report for testing content of ceramic particles in coating
Element Wt％ At％
OK 05.78 16.51
Alk 00.87 01.48
Crk 93.34 82.01
Matrix Correction ZAF
The following data, together with the description and figures 4 and 5, will be evident: the chromium-based ceramic composite coating of the invention contains 2-6 vol% of ceramic particles (Al)2O3) 40-100 micro cracks/mm, high coating hardness of 800-1200HV0.1The micro-crack oil storage performance is good, the lubricating condition is improved, the friction loss is reduced, the wear resistance is higher, the service life of the piston ring is more than 5 times that of a common chromium-plated piston ring, and the problem that the traditional piston ring is easy to have cylinder scuffing is effectively solved.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention are equivalent to or changed within the technical scope of the present invention.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention are equivalent to or changed within the technical scope of the present invention.

Claims (6)

1. The chromium-based ceramic composite plating process for the piston ring is characterized by comprising the following steps of:
step 1: clamping, sealing and cleaning mouth
S1: drawing the corresponding clamping fixture;
s2: placing the demagnetized piston ring on a special angle iron to align the opening of the piston ring;
s3: horizontally arranging a piston ring with an opening aligned with the height equal to the clamping length of the shaft on a mandrel in the semicircular tile;
s4: coating varnish into an opening gap of a piston ring by using a special tool, staggering the opening of the piston ring by about 90 degrees, starting a pneumatic valve, sleeving a corresponding nut on a mandrel, and tightening by using a wrench;
s5: moving the shaft with the piston ring on the support, brushing varnish on the surface of the piston ring by using an iron brush, and wiping the opening part by using cotton yarn dipped in acetone within a range of nearly 45 degrees to wipe off the redundant varnish as much as possible;
step 2: examination of
A1, checking and clamping: checking that the closed gap of the piston ring is within the range of 0.15-0.25mm, the excircle surface is smooth after clamping, the condition of unevenness is not allowed to exist, the ring is not allowed to be broken, otherwise, the clamping and re-assembling are removed, and the clamped piston ring is placed at the next stop point after being qualified;
a2, checking and sealing: visually checking whether all piston rings are sealed and whether the piston ring with a large opening gap is solid or not, and if not, sealing again;
a3, inspection and mouth cleaning: visually checking whether all the residual varnish of the piston ring is brushed cleanly or not, wherein the residual varnish comprises an outer circular surface, a chamfer and an opening, and placing the piston ring at the next stop point after the residual varnish is qualified;
and step 3: sand blasting and rinsing
B1: picking up a piston ring to be processed from a corresponding stop point;
b2: starting the air pressure to start the sand blasting machine to idle for a stroke, checking whether the air pressure is normal or not, and filling an equipment daily check table;
b3: the granularity of the sand for sand blasting is W63;
b4: installing a conductive rod and a plastic upper protective sleeve, screwing the copper conductive rod by a wrench, and putting the copper conductive rod into a sand blasting machine;
b5: turning on a power switch, automatically operating the sand blasting machine to blast sand for one stroke, and annularly blasting each cylinder of piston for two strokes;
b6: after the sand blasting is finished, the piston ring is lifted out of the sand blasting machine, and whether the ring body is completely blasted and the color is uniform and is in tile gray is visually observed;
b7: the piston ring after sand blasting is rinsed in a rinsing tank and then sprayed in a high-pressure water spraying tank to remove residual sand grains on the surface of the ring body and check whether the seal is intact;
b8: replacing the sand water in the sand blasting machine every week, wherein the proportion of the sand water is 15-20%;
and 4, step 4: electroplating of
C1: picking up the piston ring to be plated from the corresponding stop point;
c2: confirming the temperature of the bath solution: 60 +/-1 ℃;
c3: and (3) confirming the chemical components of the bath solution:
chromium trioxide: 200 to 280g/L
Sulfuric acid: 2.0 to 2.8g/L
Methanesulfonic acid: 1.5 to 1.8g/L
Anhydrous potassium fluoride: 5.6 to 6.0g/L
Basic lead carbonate: 0.5 to 1.5g/L
Alumina: 10 to 30g/L
Trivalent chromium ion: 1 to 8g/L
A positive ferric ion: less than or equal to 10g/L
C4: selecting an electroplating process number according to the machine type and filling a chromium plating procedure operation record table;
c5: the determination of the electroplating process number is set by a specially-assigned person according to a set basis;
c6: aligning the workpiece to a lower groove in the center of the cathode ring, preventing the workpiece from colliding with the cathode ring, and knocking the conductive copper disc by using a wood hammer or a lead bar after the cathode ring is contacted with the conductive copper disc so as to enable the conductive copper disc to be tightly contacted with the cathode ring;
c7: confirming the process number again, and pressing a start key;
c8: pressing a stop key to lift the workpiece out of the bath to flush residual bath;
c9: putting the workpiece into a cleaning and recycling tank, and cleaning and recycling a small part of residual plating solution to avoid environmental pollution and waste;
and 5: polishing and removing clamp after plating
D1: picking up a piston ring to be thrown from a corresponding stopping point;
d2: checking whether the polishing machine works normally;
d3: checking whether the abrasive belt meets the process requirements;
d4: placing the plated piston ring on a machine tool, starting a power supply, and automatically operating and polishing by a polishing machine for two strokes;
d5: and (3) polishing inspection: after polishing, the surface of the chromium plating layer is checked by naked eyes, and no obvious burr chromium tumor is confirmed;
d6: after the inspection is qualified, the clamp is removed and the cleaning is carried out;
step 6: dehydrogenation
F1: picking up a piston ring to be processed from a corresponding stop point;
f2: checking whether the temperature setting of the oven is 210 ℃ or not, and checking whether the air blowing effect of the oven is normal or not;
f3: the dehydrogenation temperature is 210 +/-10 ℃, the dehydrogenation time of the nodular cast iron piston ring is 4 hours +/-5 minutes, and the dehydrogenation time of the gray cast iron piston ring is 3 hours +/-5 minutes;
f4: the piston ring to be dehydrogenated is arranged in an oven, and the piston ring in the oven does not exceed 16 rods each time;
f5: closing the oven door, opening a power switch to remove hydrogen, keeping the temperature for a corresponding time after reaching the temperature, cutting off the power supply, and cooling in air to normal temperature;
f6: the piston ring in the oven is moved out of the oven, and is placed on a working table surface to be detected in order after demagnetization;
and 7: examination of
The method comprises the following steps of (1) inspecting the appearance, magnetism, coating thickness, bonding strength, ceramic particle components, ceramic particle size, ceramic particle hardness, coating microcrack density and coating ceramic particle content to determine whether the process requirements are met;
and 8: sampling and checking
And (4) performing subsequent spot inspection on the qualified products in the step (7), and packaging and warehousing after the qualified products are qualified.
2. The chrome-based ceramic composite plating process for piston rings as claimed in claim 1, wherein the gas pressure in B2 is: 5.5-6.5kgf/cm2。
3. The chrome-based ceramic composite plating process for piston rings as claimed in claim 1, wherein the setting data in C5 is as follows:
current density of upper and lower layers: 90 +/-5A/dm2Time 120-;
positive plating current density: 70 +/-5A/dm2Time 1000-;
composite plating current density: 70 +/-5A/dm2Time 700 and 750 seconds;
composite corrosion current density: 50 +/-5A/dm2Time is 70-78 seconds;
the number of plating cycles N is determined by the plating thickness.
4. The chrome-based ceramic composite plating process for piston rings as claimed in claim 1, wherein the process requirements of the abrasive belt in D3 are as follows: the granularity of the abrasive belt is 240#, and one abrasive belt is replaced when 10 cylinders are thrown.
5. The chromium-based ceramic composite plating process for piston rings as claimed in claim 1, wherein the process requirements in step 7 are as follows:
appearance:
a: the coating is not allowed to have bubbles, fall off, pockmarks, collapse openings, slag inclusion, no coating on the surface, no peeling, dovetail and fish scale stripes and no micro cracks visible to naked eyes;
b: the plating layer should not have serious chrome nodules, and the chrome nodules at local points should be less than or equal to 0.30 mm;
c: pinhole of the outer disc: the maximum size of the pinhole is less than or equal to 0.20 mm;
d: coating excircle edge: the edge of the excircle should not have minor saw-tooth shape and unevenness defects;
e: the boundary line of the joint surface of the ring land embedded with the piston ring and the plating layer is clear, and the plating layer is not allowed to exist on the surface of the ring land;
magnetism: the method is based on the condition of unobvious iron-absorbing ash;
coating thickness: performing according to relevant process requirements;
bonding strength: the coating should not separate from the substrate, fragments of the coating should not exceed half the thickness of the coating;
ceramic particle composition: aluminum oxide;
ceramic particle size: the diameter is 0.5-5 um;
hardness of ceramic particles: 2200-3000HV 0.025;
coating hardness: 800-1200HV0.1；
Plating layer microcrack density: 40-100 strips/mm;
the content of the ceramic particles of the plating layer is as follows: 2-6% (volume), 1.1-3.3% (weight), 0.6-1.7% (aluminum).
6. The chromium-based ceramic composite plating process for piston rings as claimed in claim 1, wherein the specific method in step 8 is as follows:
the appearance is checked by 100 percent by visual inspection;
sampling the thickness of the plating layer for detection: the gap of each non-embedded piston ring station is measured by a gap ring for a flow inspector, 1 piston ring is taken per shift for measuring the thickness of a coating by a metallographic microscope, and the external grinding size is accurate by embedding the piston ring.
Bonding strength: detecting the bonding strength of 1 piston ring in each shift, detecting the nodular cast iron piston ring by a twisting method, performing visual inspection after the two opening surfaces are twisted by 90 degrees, and detecting the gray cast iron piston ring by a breaking method;
sampling and detecting the hardness and the density of microcracks of the plating layer: detecting the hardness and the density of microcracks of the plating layer by drawing 1 piston ring per shift;
content of ceramic particles: the weight of the piston ring before chromium stripping is G1, the weight of the piston ring after chromium stripping is G2, the weight of the coating is G1-G2, the ceramic particles after chromium stripping are filtered out, the ceramic particles are dried and weighed G3, the content of the ceramic particles is G3 x 100/G, and the detection is carried out for 1 time per month.
CN202110889456.8A 2021-08-04 2021-08-04 Composite plating process for chromium-base ceramic of piston ring Pending CN113584548A (en)

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CN101597781A (en) * 2009-07-02 2009-12-09 南京飞燕活塞环股份有限公司 A kind of high hardness nodular iron piston ring chromium plating process
CN101839341A (en) * 2009-11-14 2010-09-22 襄樊新立恒星活塞环有限责任公司 Piston ring and surface spongy chromium plating technique thereof

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CN201162585Y (en) * 2008-01-16 2008-12-10 中外合资安庆帝伯格茨活塞环有限公司 Abrasion-proof piston ring
CN101597781A (en) * 2009-07-02 2009-12-09 南京飞燕活塞环股份有限公司 A kind of high hardness nodular iron piston ring chromium plating process
CN101839341A (en) * 2009-11-14 2010-09-22 襄樊新立恒星活塞环有限责任公司 Piston ring and surface spongy chromium plating technique thereof

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CN117071041A (en) * 2023-10-13 2023-11-17 苏州派普机械有限公司 Electroplating equipment for petrochemical parts
CN117071041B (en) * 2023-10-13 2023-12-29 苏州派普机械有限公司 Electroplating equipment for petrochemical parts

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