US20190161845A1 - Surface modified steel member with anti-corrosion properties and method for modifying surface of steel material - Google Patents
Surface modified steel member with anti-corrosion properties and method for modifying surface of steel material Download PDFInfo
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- US20190161845A1 US20190161845A1 US16/263,226 US201916263226A US2019161845A1 US 20190161845 A1 US20190161845 A1 US 20190161845A1 US 201916263226 A US201916263226 A US 201916263226A US 2019161845 A1 US2019161845 A1 US 2019161845A1
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C10/00—Solid state diffusion of only metal elements or silicon into metallic material surfaces
- C23C10/28—Solid state diffusion of only metal elements or silicon into metallic material surfaces using solids, e.g. powders, pastes
- C23C10/34—Embedding in a powder mixture, i.e. pack cementation
- C23C10/52—Embedding in a powder mixture, i.e. pack cementation more than one element being diffused in one step
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C10/00—Solid state diffusion of only metal elements or silicon into metallic material surfaces
- C23C10/02—Pretreatment of the material to be coated
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C10/00—Solid state diffusion of only metal elements or silicon into metallic material surfaces
- C23C10/28—Solid state diffusion of only metal elements or silicon into metallic material surfaces using solids, e.g. powders, pastes
- C23C10/34—Embedding in a powder mixture, i.e. pack cementation
- C23C10/36—Embedding in a powder mixture, i.e. pack cementation only one element being diffused
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C10/00—Solid state diffusion of only metal elements or silicon into metallic material surfaces
- C23C10/60—After-treatment
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/02—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/02—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material
- C23C28/021—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material including at least one metal alloy layer
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/02—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material
- C23C28/023—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material only coatings of metal elements only
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/02—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material
- C23C28/023—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material only coatings of metal elements only
- C23C28/025—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material only coatings of metal elements only with at least one zinc-based layer
Definitions
- the disclosure relates to surface modified steel members, and more particularly, to a surface modified steel member with anti-corrosion property and a method for making the same.
- Corrosion of steel causes huge losses to the world. According to researches, steel which is scrapped because of corrosion every year accounts for more than 20% of annual steel production, causing a value of loss about 7000 hundred million dollars. The loss value is far more than the total loss value caused by natural calamities such as earthquake, flood, and typhoon.
- some anti-corrosion technologies are developed to ease the steel corrosion.
- the protective coatings made by the anti-corrosion technologies are not a complete answer to corrosion, and the hardness thereof is low.
- Nickel and zinc pretreatment technologies can allow the steel material to have higher corrosion resistance, higher wear resistance, and high vibration resistance. Thus, it is needed to use nickel and zinc pretreatment technologies to manufacture a surface modified steel structure with anti-corrosion.
- FIG. 1 is a flowchart of an embodiment of a method for modifying surface of steel material according to the present disclosure.
- FIG. 2 is a diagrammatic view of an embodiment of a surface modified steel member.
- FIG. 3 is a metallographic view of a cross-section of a surface modified steel member made by steel substrate of steel Q235 which is not quenched and tempered.
- FIG. 4 is a metallographic view of a cross-section of a surface modified steel member made by steel substrate of steel No. 20 which is not quenched and tempered.
- FIG. 5 is a metallographic view of a cross-section of a surface modified steel member made by steel substrate of 20MnTiB which is subjected to a quenching and tempering process.
- FIG. 6 is metallographic view of a cross-section of a surface modified steel member made by steel substrate of 25CrMoV which is subjected to a quenching and tempering process.
- FIG. 1 illustrates an embodiment of a method for modifying surface of steel material.
- the method is provided by way of embodiments, as there are a variety of ways to carry out the method.
- Each block shown in FIG. 1 represents one or more processes, methods, or subroutines, carried out in the example method.
- the illustrated order of blocks is illustrative only and the order of the blocks can change. Additional blocks can be added or fewer blocks may be utilized or the order of the blocks may be changed, without departing from this disclosure.
- the method can begin at block 11 .
- a steel substrate is provided, which is made of low-carbon steel or low-carbon alloy steel.
- the low-carbon steel includes carbon element, and the carbon element has a content of less than 0.25% in the carbon steel by weight.
- the low-carbon alloy steel is alloy steel including carbon element and alloy element, and the carbon element has a content of less than 0.25% in the low-carbon alloy steel by weight.
- the steel substrate is made of one of steel Q235, steel No. 20, steel 20MnTiB, and steel 25CrMoV.
- the steel substrate is subjected to pretreatment to clean surface of the steel substrate.
- the pretreatment includes cleaning of oil and grease adhering to the surface by alkaline solution, by ultrasonic waves, or by heating.
- the pretreatment further includes cleaning of rust on the surface by grit blasting.
- the alkaline solution can include a basic salt, and the basic salt includes at least one of caustic soda, sodium carbonate, sodium phosphate tribasic, sodium silicate, and sodium borate. Furthermore, the alkaline solution can further include a steel chelating agent and an organic additive agent to improve the surface cleaning.
- the steel chelating agent includes at least one of elhylene diamine tetraacetic acid (EDTA), sodium citrate, and triethanolamine.
- the organic additive agent includes at least one of ethylene glycol and ethylene glycol monoethyl ether.
- Ultrasonic cleaning is using ultrasound waves (usually from 20-400 kHz) to agitate washing fluid, thereby producing high forces on the oil and the grease adhering to the surface.
- the washing fluid can be water, or other solvents appropriate for the steel substrate to enhance the cleaning.
- Cleaning by heating is heating the steel substrate to a temperature equal to or higher than the ignition point of the oil and the grease, thereby causing the oil and the grease to be burned off and volatilized.
- Grit blasting forcibly propels a stream of small hard balls under high pressure to remove rust and oxide skin, thereby allowing the surface to obtain desired roughness and brightness.
- a penetrating agent is provided.
- the penetrating agent is in a form of powders, which includes Zn powder in a range from 15% to 20% by weight, Ni powder in a range from 3% to 4% by weight, Al powder in a range from 2% to 2.5% by weight, rare earth metallic powder in a range from 2% to 3% by weight, ammonia chloride in a range from 1% to 4% by weight, and Al 2 O 3 powder in a remaining range by weight.
- Specific concentration of each type of powder in the penetrating agent can be varied according to the material of the steel substrate or the main intended application of the surface modified steel structure.
- the steel substrate after the pretreatment and the penetrating agent are loaded into an enclosed steel container.
- the steel container is heated to a temperature in a range from 370 degrees Celsius to 450 degrees Celsius, and is rotated at a speed in a range from 5 Revolutions Per minute (RPM) to 10 RPM during the heating.
- RPM Revolutions Per minute
- the speed for rotating the steel container ensures even heating of the penetrating agent and the steel substrate.
- the penetrating agent evenly penetrates into the steel substrate.
- the temperature for heating the steel container is also important, a higher temperature provides a significantly larger penetrating rate by the atoms in the penetrating agent.
- the specific temperature for heating can be varied according to the material of the steel substrate or the intended application of the surface modified steel member.
- a time period for heating the steel container (that is, a time period for the surface modification) is in a range from 1 hour to 10 hours.
- the specific time period for heating the steel container can also be varied according to the material of the steel substrate or the main intended application of the surface modified steel member.
- the steel substrate can be preheated to a temperature from 400 degrees Celsius to 420 degrees Celsius, and the preheated steel substrate and the penetrating agent are mixed and loaded into the steel container. In other embodiments, the steel substrate is not preheated, and the steel substrate and the penetrating agent are both at room temperature when loaded into the steel substrate.
- the steel substrate after surface modification is allowed to naturally cool. After removing dust on the surface, the steel substrate is then washed by water to remove remaining powders and other impurities.
- FIG. 2 illustrates an embodiment of a surface modified steel member 100 with anti-corrosion properties.
- the surface modified steel member 100 includes a steel substrate 10 , a metallic diffusion layer 20 formed on the steel substrate 10 , and an alloy deposition layer 30 formed on the metallic diffusion layer 20 .
- the metallic diffusion layer 20 defines a transition region between the steel substrate 10 and the alloy deposition layer 30 .
- the metallic diffusion layer 20 includes pearlite crystals and ferrite crystals.
- the alloy deposition layer 30 includes zinc ferrum alloy.
- the thickness of the metallic diffusion layer 20 is in a range from 30 microns to 120 microns.
- the thickness of the alloy deposition layer 30 is in a range from 60 microns to 110 microns.
- the metallic diffusion layer 20 has a Micro Vickers Hardness greater than that of the steel substrate 10 after surface modification.
- the Micro Vickers Hardness of the steel substrate 10 is in a range from 150 to 260, and the Micro Vickers Hardness of the metallic diffusion layer 20 is in a range from 200 to 400.
- quenching and tempering structures such as tempered sorbate, are formed on the surface of the steel substrate 10 .
- the metallic diffusion layer 20 has a Micro Vickers Hardness greater than that of the steel substrate 10 after surface modification. In this embodiment, the Micro Vickers Hardness of each of the steel substrate 10 and the metallic diffusion layer 20 is in a range from 260 to 450.
- the concentration of the pearlite crystals in the metallic diffusion layer 20 decreases along a direction from the alloy deposition layer 30 to the steel substrate 10 .
- the concentration of the ferrite crystals in the metallic diffusion layer 20 increases along the direction from the alloy deposition layer 30 to the steel substrate 10 .
- the concentration of the pearlite crystals in a region of the metallic diffusion layer 20 facing the alloy deposition layer 30 is in a range from 65% to 85%.
- the concentration of the ferrite crystals in the region is in a range from 15% to 35%.
- a steel substrate of steel Q235, not quenched and tempered, was provided.
- the steel substrate was subjected to a pretreatment, including cleaning of oil and grease by alkaline solution and removal of rust by grit blasting.
- a penetrating agent was provided, including Zn powder of 15% by weight, Ni powder of 4% by weight, Al powder of 2% by weight, rare earth metallic powder of 3% by weight, ammonia chloride of 1% by weight, and Al 2 O 3 powder of 75% by weight.
- the steel substrate after the pretreatment and the penetrating agent were both at room temperature when loaded to an enclosed steel container.
- the steel container was heated to a temperature from 420 degrees Celsius for 1 hour, and was rotated at a speed of 5 RPM during the heating to perform surface modification.
- the steel substrate after surface modification was washed by water to obtain the surface modified steel member.
- the steel substrate was subjected to the same pretreatment and the same surface modification to obtain the surface modified steel member.
- FIGS. 3 and 4 show that each of the two surface modified steel members in the Embodiment 1 includes two metallographic structural layers formed on the steel substrate, that is, an outer alloy deposition layer and an inner metallic diffusion layer.
- the color of the pearlite crystals in metallic diffusion layer is lighter than the color of the pearlite crystals in the steel substrate.
- the thickness of the metallic diffusion layer is in a range from 30 microns to 80 microns.
- the hardness of each of the two surface modified steel members was further tested. Results shows that the Micro Vickers Hardness of the metallic diffusion layer is greater than the Micro Vickers Hardness of the steel substrate. Moreover, the concentration of the pearlite crystals in the metallic diffusion layer decreases along a direction from the alloy deposition layer to the steel substrate. The concentration of the pearlite crystals in a region of the metallic diffusion layer facing the alloy deposition layer is 65%. The concentration of the ferrite crystals in the metallic diffusion layer increases along the direction from the alloy deposition layer to the steel substrate. The concentration of the ferrite in the region is 35%.
- a steel substrate of steel 20MnTiB was provided.
- the steel substrate was subjected to a quenching and tempering process.
- the steel substrate was then subjected to the same pretreatment.
- a penetrating agent was provided, including Zn powder of 20% by weight, Ni powder of 3% by weight, Al powder of 2.5% by weight, rare earth metallic powder of 2% by weight, ammonia chloride of 4% by weight, and Al 2 O 3 powder of 68.5% by weight.
- the steel substrate after the pretreatment and the penetrating agent were both at room temperature when loaded to an enclosed steel container.
- the steel container was heated to a temperature from 370 degrees Celsius for 10 hours, and was rotated at a speed of 8 RPM during the heating to perform surface modification.
- the steel substrate after surface modification was washed by water to obtain the surface modified steel member.
- a steel substrate of steel 25CrMoV was also provided.
- the steel substrate was subjected to a quenching and tempering process.
- the steel substrate was then subjected to the same pretreatment and surface modification to obtain the surface modified steel member.
- FIGS. 5 and 6 show that each of the two surface modified steel members in the Embodiment 2 also includes two metallographic structural layers formed on the steel substrate, that is, an outer alloy deposition layer and an inner metallic diffusion layer.
- the thickness of the metallic diffusion layer is in a range from 80 microns to 120 microns.
- the quenching and tempering process for the steel substrate forms quenching and tempering structures in the metallic diffusion layer.
- Each of the two surface modified steel members was subjected to an etching process by immersing the surface modified steel member in an etchant including nitric acid and alcohol, with a concentration from 1% to 5%. Results show that a bright white color remains on the metallic diffusion layer after several seconds, indicating that each surface modified steel member has a good corrosion resistance.
- Each of the two surface modified steel members were further subjected to a neutral salt spray (NSS) test and a sulfur dioxide test. Results show that the surface-modified steel member generates no red rust after 2400 hours in the NSS test, and also generates no red rust after 240 hours in the sulfur dioxide test, which further indicating that each surface modified steel member has good corrosion resistance.
- NSS neutral salt spray
- the hardness of each of the two surface modified steel members was further tested. Results show that the Micro Vickers Hardness of the metallic diffusion layer is not greater than the Micro Vickers Hardness of the steel substrate after being quenched and tempered. Moreover, the concentration of the pearlite crystals in the metallic diffusion layer decreases along a direction from the alloy deposition layer to the steel substrate. The concentration of the pearlite crystals in a region of the metallic diffusion layer facing the alloy deposition layer is in a range from 75% to 85%. The concentration of the ferrite crystals in the metallic diffusion layer increases along the direction from the alloy deposition layer to the steel substrate. The concentration of the ferrite crystals in the region is in a range from 15% to 25%.
- the surface modified steel structure according to the present disclosure has a good corrosion resistance, which can reduce the losses caused by steel corrosion. Furthermore, the basic mechanical properties of the steel substrate are not changed, but the abrasion resistance of the steel substrate is improved because of the high hardness imparted by these processes.
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Abstract
Description
- This application claims all benefits accruing under 35 U.S.C. § 119 from China Patent Application No. 201610690166.X, filed on Aug. 19, 2016 in the China National Intellectual Property Administration, the content of which is hereby incorporated by reference. This application is a continuation-in-part under 35 U.S.C. § 120 of international patent application PCT/CN2017/091031 filed Jun. 30, 2017.
- The disclosure relates to surface modified steel members, and more particularly, to a surface modified steel member with anti-corrosion property and a method for making the same.
- Corrosion of steel causes huge losses to the world. According to researches, steel which is scrapped because of corrosion every year accounts for more than 20% of annual steel production, causing a value of loss about 7000 hundred million dollars. The loss value is far more than the total loss value caused by natural calamities such as earthquake, flood, and typhoon. Nowadays, some anti-corrosion technologies are developed to ease the steel corrosion. However, the protective coatings made by the anti-corrosion technologies are not a complete answer to corrosion, and the hardness thereof is low. Nickel and zinc pretreatment technologies can allow the steel material to have higher corrosion resistance, higher wear resistance, and high vibration resistance. Thus, it is needed to use nickel and zinc pretreatment technologies to manufacture a surface modified steel structure with anti-corrosion.
- Implementations of the disclosure will now be described, by way of embodiments only, with reference to the attached figures.
-
FIG. 1 is a flowchart of an embodiment of a method for modifying surface of steel material according to the present disclosure. -
FIG. 2 is a diagrammatic view of an embodiment of a surface modified steel member. -
FIG. 3 is a metallographic view of a cross-section of a surface modified steel member made by steel substrate of steel Q235 which is not quenched and tempered. -
FIG. 4 is a metallographic view of a cross-section of a surface modified steel member made by steel substrate of steel No. 20 which is not quenched and tempered. -
FIG. 5 is a metallographic view of a cross-section of a surface modified steel member made by steel substrate of 20MnTiB which is subjected to a quenching and tempering process. -
FIG. 6 is metallographic view of a cross-section of a surface modified steel member made by steel substrate of 25CrMoV which is subjected to a quenching and tempering process. - It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous components. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure.
-
FIG. 1 illustrates an embodiment of a method for modifying surface of steel material. The method is provided by way of embodiments, as there are a variety of ways to carry out the method. Each block shown inFIG. 1 represents one or more processes, methods, or subroutines, carried out in the example method. Furthermore, the illustrated order of blocks is illustrative only and the order of the blocks can change. Additional blocks can be added or fewer blocks may be utilized or the order of the blocks may be changed, without departing from this disclosure. The method can begin atblock 11. - At
block 11, a steel substrate is provided, which is made of low-carbon steel or low-carbon alloy steel. - The low-carbon steel includes carbon element, and the carbon element has a content of less than 0.25% in the carbon steel by weight. The low-carbon alloy steel is alloy steel including carbon element and alloy element, and the carbon element has a content of less than 0.25% in the low-carbon alloy steel by weight.
- In an embodiment, the steel substrate is made of one of steel Q235, steel No. 20, steel 20MnTiB, and steel 25CrMoV.
- At
block 12, the steel substrate is subjected to pretreatment to clean surface of the steel substrate. - In an embodiment, the pretreatment includes cleaning of oil and grease adhering to the surface by alkaline solution, by ultrasonic waves, or by heating. The pretreatment further includes cleaning of rust on the surface by grit blasting.
- Cleaning of contaminants adhering to the surface, such as oil, grease, and dust since the contaminants can be carbonized during heating. If formed, such carbonization layer might affect the appearances and the following surface modification processes.
- The alkaline solution can include a basic salt, and the basic salt includes at least one of caustic soda, sodium carbonate, sodium phosphate tribasic, sodium silicate, and sodium borate. Furthermore, the alkaline solution can further include a steel chelating agent and an organic additive agent to improve the surface cleaning. The steel chelating agent includes at least one of elhylene diamine tetraacetic acid (EDTA), sodium citrate, and triethanolamine. The organic additive agent includes at least one of ethylene glycol and ethylene glycol monoethyl ether.
- Cleaning by ultrasonic waves (ultrasonic cleaning) is using ultrasound waves (usually from 20-400 kHz) to agitate washing fluid, thereby producing high forces on the oil and the grease adhering to the surface. The washing fluid can be water, or other solvents appropriate for the steel substrate to enhance the cleaning.
- Cleaning by heating is heating the steel substrate to a temperature equal to or higher than the ignition point of the oil and the grease, thereby causing the oil and the grease to be burned off and volatilized.
- Grit blasting forcibly propels a stream of small hard balls under high pressure to remove rust and oxide skin, thereby allowing the surface to obtain desired roughness and brightness.
- At
block 13, a penetrating agent is provided. The penetrating agent is in a form of powders, which includes Zn powder in a range from 15% to 20% by weight, Ni powder in a range from 3% to 4% by weight, Al powder in a range from 2% to 2.5% by weight, rare earth metallic powder in a range from 2% to 3% by weight, ammonia chloride in a range from 1% to 4% by weight, and Al2O3 powder in a remaining range by weight. - Specific concentration of each type of powder in the penetrating agent can be varied according to the material of the steel substrate or the main intended application of the surface modified steel structure.
- At
block 14, the steel substrate after the pretreatment and the penetrating agent are loaded into an enclosed steel container. The steel container is heated to a temperature in a range from 370 degrees Celsius to 450 degrees Celsius, and is rotated at a speed in a range from 5 Revolutions Per minute (RPM) to 10 RPM during the heating. By conduction heating of the penetrating agent and the steel substrate, the steel substrate and the penetrating agent can be at same temperature, and the penetrating agent can penetrate into the steel substrate to modify the surface of the steel substrate. - The speed for rotating the steel container ensures even heating of the penetrating agent and the steel substrate. Thus, the penetrating agent evenly penetrates into the steel substrate. The temperature for heating the steel container is also important, a higher temperature provides a significantly larger penetrating rate by the atoms in the penetrating agent. The specific temperature for heating can be varied according to the material of the steel substrate or the intended application of the surface modified steel member.
- In an embodiment, a time period for heating the steel container (that is, a time period for the surface modification) is in a range from 1 hour to 10 hours. The specific time period for heating the steel container can also be varied according to the material of the steel substrate or the main intended application of the surface modified steel member.
- In an embodiment, the steel substrate can be preheated to a temperature from 400 degrees Celsius to 420 degrees Celsius, and the preheated steel substrate and the penetrating agent are mixed and loaded into the steel container. In other embodiments, the steel substrate is not preheated, and the steel substrate and the penetrating agent are both at room temperature when loaded into the steel substrate.
- At
block 15, the steel substrate after surface modification is washed, thereby obtaining the surface modified steel member. - In an embodiment, the steel substrate after surface modification is allowed to naturally cool. After removing dust on the surface, the steel substrate is then washed by water to remove remaining powders and other impurities.
-
FIG. 2 illustrates an embodiment of a surface modifiedsteel member 100 with anti-corrosion properties. The surface modifiedsteel member 100 includes asteel substrate 10, ametallic diffusion layer 20 formed on thesteel substrate 10, and analloy deposition layer 30 formed on themetallic diffusion layer 20. Themetallic diffusion layer 20 defines a transition region between thesteel substrate 10 and thealloy deposition layer 30. Themetallic diffusion layer 20 includes pearlite crystals and ferrite crystals. Thealloy deposition layer 30 includes zinc ferrum alloy. In an embodiment, the thickness of themetallic diffusion layer 20 is in a range from 30 microns to 120 microns. The thickness of thealloy deposition layer 30 is in a range from 60 microns to 110 microns. - If the
steel substrate 10 is not quenched and tempered before surface modification, themetallic diffusion layer 20 has a Micro Vickers Hardness greater than that of thesteel substrate 10 after surface modification. The Micro Vickers Hardness of thesteel substrate 10 is in a range from 150 to 260, and the Micro Vickers Hardness of themetallic diffusion layer 20 is in a range from 200 to 400. In another embodiment, if thesteel substrate 10 is subjected to a quenching and tempering process beforehand, quenching and tempering structures, such as tempered sorbate, are formed on the surface of thesteel substrate 10. Themetallic diffusion layer 20 has a Micro Vickers Hardness greater than that of thesteel substrate 10 after surface modification. In this embodiment, the Micro Vickers Hardness of each of thesteel substrate 10 and themetallic diffusion layer 20 is in a range from 260 to 450. - In an embodiment, the concentration of the pearlite crystals in the
metallic diffusion layer 20 decreases along a direction from thealloy deposition layer 30 to thesteel substrate 10. The concentration of the ferrite crystals in themetallic diffusion layer 20 increases along the direction from thealloy deposition layer 30 to thesteel substrate 10. In an embodiment, the concentration of the pearlite crystals in a region of themetallic diffusion layer 20 facing thealloy deposition layer 30 is in a range from 65% to 85%. The concentration of the ferrite crystals in the region is in a range from 15% to 35%. - A steel substrate of steel Q235, not quenched and tempered, was provided. The steel substrate was subjected to a pretreatment, including cleaning of oil and grease by alkaline solution and removal of rust by grit blasting. A penetrating agent was provided, including Zn powder of 15% by weight, Ni powder of 4% by weight, Al powder of 2% by weight, rare earth metallic powder of 3% by weight, ammonia chloride of 1% by weight, and Al2O3 powder of 75% by weight. The steel substrate after the pretreatment and the penetrating agent were both at room temperature when loaded to an enclosed steel container. The steel container was heated to a temperature from 420 degrees Celsius for 1 hour, and was rotated at a speed of 5 RPM during the heating to perform surface modification. The steel substrate after surface modification was washed by water to obtain the surface modified steel member.
- A steel substrate of steel No. 20, not quenched and tempered, was also provided. The steel substrate was subjected to the same pretreatment and the same surface modification to obtain the surface modified steel member.
-
FIGS. 3 and 4 show that each of the two surface modified steel members in the Embodiment 1 includes two metallographic structural layers formed on the steel substrate, that is, an outer alloy deposition layer and an inner metallic diffusion layer. Referring toFIGS. 3 and 4 , the color of the pearlite crystals in metallic diffusion layer is lighter than the color of the pearlite crystals in the steel substrate. The thickness of the metallic diffusion layer is in a range from 30 microns to 80 microns. - The hardness of each of the two surface modified steel members was further tested. Results shows that the Micro Vickers Hardness of the metallic diffusion layer is greater than the Micro Vickers Hardness of the steel substrate. Moreover, the concentration of the pearlite crystals in the metallic diffusion layer decreases along a direction from the alloy deposition layer to the steel substrate. The concentration of the pearlite crystals in a region of the metallic diffusion layer facing the alloy deposition layer is 65%. The concentration of the ferrite crystals in the metallic diffusion layer increases along the direction from the alloy deposition layer to the steel substrate. The concentration of the ferrite in the region is 35%.
- A steel substrate of steel 20MnTiB was provided. The steel substrate was subjected to a quenching and tempering process. The steel substrate was then subjected to the same pretreatment. A penetrating agent was provided, including Zn powder of 20% by weight, Ni powder of 3% by weight, Al powder of 2.5% by weight, rare earth metallic powder of 2% by weight, ammonia chloride of 4% by weight, and Al2O3 powder of 68.5% by weight. The steel substrate after the pretreatment and the penetrating agent were both at room temperature when loaded to an enclosed steel container. The steel container was heated to a temperature from 370 degrees Celsius for 10 hours, and was rotated at a speed of 8 RPM during the heating to perform surface modification. The steel substrate after surface modification was washed by water to obtain the surface modified steel member.
- A steel substrate of steel 25CrMoV was also provided. The steel substrate was subjected to a quenching and tempering process. The steel substrate was then subjected to the same pretreatment and surface modification to obtain the surface modified steel member.
-
FIGS. 5 and 6 show that each of the two surface modified steel members in the Embodiment 2 also includes two metallographic structural layers formed on the steel substrate, that is, an outer alloy deposition layer and an inner metallic diffusion layer. The thickness of the metallic diffusion layer is in a range from 80 microns to 120 microns. The quenching and tempering process for the steel substrate forms quenching and tempering structures in the metallic diffusion layer. - Each of the two surface modified steel members was subjected to an etching process by immersing the surface modified steel member in an etchant including nitric acid and alcohol, with a concentration from 1% to 5%. Results show that a bright white color remains on the metallic diffusion layer after several seconds, indicating that each surface modified steel member has a good corrosion resistance. Each of the two surface modified steel members were further subjected to a neutral salt spray (NSS) test and a sulfur dioxide test. Results show that the surface-modified steel member generates no red rust after 2400 hours in the NSS test, and also generates no red rust after 240 hours in the sulfur dioxide test, which further indicating that each surface modified steel member has good corrosion resistance.
- Furthermore, the hardness of each of the two surface modified steel members was further tested. Results show that the Micro Vickers Hardness of the metallic diffusion layer is not greater than the Micro Vickers Hardness of the steel substrate after being quenched and tempered. Moreover, the concentration of the pearlite crystals in the metallic diffusion layer decreases along a direction from the alloy deposition layer to the steel substrate. The concentration of the pearlite crystals in a region of the metallic diffusion layer facing the alloy deposition layer is in a range from 75% to 85%. The concentration of the ferrite crystals in the metallic diffusion layer increases along the direction from the alloy deposition layer to the steel substrate. The concentration of the ferrite crystals in the region is in a range from 15% to 25%.
- The surface modified steel structure according to the present disclosure has a good corrosion resistance, which can reduce the losses caused by steel corrosion. Furthermore, the basic mechanical properties of the steel substrate are not changed, but the abrasion resistance of the steel substrate is improved because of the high hardness imparted by these processes.
- The embodiments shown and described above are only examples. Therefore, many commonly-known features and details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, including in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. It will, therefore, be appreciated that the embodiments described above may be modified within the scope of the claims.
Claims (15)
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CN201610690166.XA CN106435466B (en) | 2016-08-19 | 2016-08-19 | Steel surface modification structure formed by utilizing zinc-nickel infiltration layer and preparation method thereof |
CN201610690166.X | 2016-08-19 | ||
PCT/CN2017/091031 WO2018032887A1 (en) | 2016-08-19 | 2017-06-30 | Steel surface-modified structure formed using zinc-nickel infiltration layer, and method for fabrication thereof |
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CN108220903B (en) * | 2018-01-12 | 2020-02-18 | 和县隆盛精密机械有限公司 | Surface treatment process for metal stamping part of numerical control machine tool |
CN111893430B (en) * | 2020-08-05 | 2021-07-13 | 江苏领嘉科技有限公司 | Solid diffusion surface anti-corrosion treatment method for carbon steel clamping and pressing pipe fitting |
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US4071638A (en) * | 1974-11-07 | 1978-01-31 | General Electric Company | Method of applying a metallic coating with improved resistance to high temperature to environmental conditions |
FR2672827A1 (en) * | 1991-02-14 | 1992-08-21 | Michelin & Cie | METALLIC WIRE COMPRISING A STEEL SUBSTRATE HAVING A WRINKLE - TYPE RECTANGULAR STRUCTURE AND A COATING; METHOD FOR OBTAINING THIS WIRE. |
CN101319300B (en) * | 2008-07-10 | 2010-08-04 | 重庆大有表面技术有限公司 | Zinc-nickel seeping layer ferrous metal corrosion protection process |
CN102127732B (en) * | 2011-03-02 | 2012-10-10 | 安徽天通达克罗涂复科技有限公司 | Complex alloy permeation agent and method for preparing permeation layer |
MX2014001118A (en) * | 2011-07-29 | 2014-02-27 | Nippon Steel & Sumitomo Metal Corp | Alloyed hot-dip zinc coat layer, steel sheet having same, and method for producing same. |
CN102766840B (en) * | 2012-08-08 | 2014-05-14 | 中国石油化工股份有限公司 | Surface modification zinc-aluminum rare earth joint-seeping method of steel heat exchanger tube bunch and seeping agent thereof |
CN102777468B (en) * | 2012-08-21 | 2014-11-19 | 重庆大有表面技术有限公司 | Production process of double-height bolt and double-height bolt produced thereby |
RU2539888C2 (en) * | 2013-02-14 | 2015-01-27 | Федеральное государственное бюджетное учреждение науки, Объединенный институт высоких температур Российской академии наук (ОИВТ РАН) | Composition for thermodiffusion galvanising of steel products |
CN105839047A (en) * | 2016-06-16 | 2016-08-10 | 福建大统铁路精密装备股份有限公司 | Zincizing infiltrated layer corrosion resistance process for metal |
CN106435466B (en) * | 2016-08-19 | 2021-08-13 | 重庆大有表面技术有限公司 | Steel surface modification structure formed by utilizing zinc-nickel infiltration layer and preparation method thereof |
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KR102411170B1 (en) | 2022-06-22 |
CN106435466A (en) | 2017-02-22 |
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KR20210076172A (en) | 2021-06-23 |
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