KR20150006433A - Improved process for diffusing a substrate into a base material - Google Patents

Abstract

An improved method for diffusing a substrate into a base material is described. In general, a process for introducing a base material into a bath having a substrate with a catalyst is provided. A selected amount of catalyst and a predetermined bath temperature sufficient to lower the activation energy of the base material are provided so that the substrate can readily diffuse into the surface of the base material. Nonetheless, certain materials within the base material can inhibit diffusion of the substrate into the surface of the base material. Thus, there is further provided a selected amount of catalyst and a predetermined bath temperature sufficient to promote the leaching of such selected materials that inhibit diffusion of such a substrate into such base material. The leached materials are substantially displaced by the diffused substrate.

Description

[0001] IMPROVED PROCESS FOR DIFFUSING A SUBSTRATE INTO A BASE MATERIAL [0002]

Inventor: Philos Jonqho Ko and Bongsub Samuel Ko

The present application is titled " Improved Method for Diffusion of Substrate into Base Material "under the name of Koh Phillose and Koh Bum Samuel as inventors, and the United States of America, filed May 4, 2012, / 642,759; No. 61 / 642,768, titled " Improved Method for Diffusing Titanium into Stainless Steel Base Material ", filed May 4, 2012; And U.S. Provisional Patent Application No. 61 / 642,781, filed May 4, 2012 entitled " METHOD FOR POLISHING STAINLESS STEEL WITH DIFFERENT TITANIUM IN THE SAME " The disclosures of which are incorporated herein by reference.

The present invention generally relates to a method for diffusing a substrate into a base meterial and a method for polishing the resulting article. In one embodiment, a method is provided for introducing a base material into a salt bath having a substrate with a catalyst. A selected amount of catalyst and a predetermined bath temperature are provided sufficient to lower the activation energy of the base material so that the substrate can diffuse into the surface of the base material. In addition, a selected amount of catalyst and predetermined bath temperature are provided sufficient to promote selective materials that inhibit diffusion of the substrate into the base material to leach from the base material.

U.S. Patent No. 6,645,566 describes a method for diffusing titanium and nitride into various base materials including steel and steel alloys, aluminum and aluminum alloys, titanium and titanium alloys. U.S. Patent No. 6,645,566 discloses a method of reducing the activation energy of the base material and changing the amount of catalyst sufficient to promote leaching of selected materials from the base material and increasing the process temperature for a certain time Describes various embodiments for increasing the effectiveness of the method described therein by manipulation. Thus, one object of the present invention is to provide a method of reducing the activation energy of the base material and reducing the activation energy of the base material as described in U.S. Patent No. 6,645,566 by varying the process steps sufficient to facilitate the leaching of the selected materials from the base material To improve the effectiveness of such methods.

For example, as described in co-pending U.S. Patent Application No. 11 / 869,399, the content of steel or steel alloy base material may be varied to improve the effectiveness of the process as described in U.S. Patent No. 6,645,566 . For example, vanadium and cobalt may be added to the steel or steel alloy base material to improve the diffusion of titanium and nitride into these (steel or steel alloy base materials), while chromium is added to the base material It is possible to suppress the diffusion of titanium and nitride into the film. It is therefore an object of the present invention to provide a method of diffusing a substrate (e.g., titanium) into a base material, which is selected to inhibit the diffusion of such a substrate (e.g., titanium) Promotes the leaching of materials (e.g., chromium).

However, as described in U.S. Patent No. 7,896,981, chromium is generally known to provide corrosion-resistance properties in some base materials (e.g., in stainless steels). Nonetheless, compared to chromium, titanium also offers corrosion resistance and other improved properties. It is therefore an object of the present invention to promote leaching of certain materials from the base material such that certain materials (e.g., chromium) are displaced by an improved corrosion resistant substrate (e.g., titanium) (E. G., Titanium) into the base material by providing a corrosion resistant substrate (e.

These and other certain advantages of the preferred embodiments of the present invention, including combinations of features of the present invention, will become apparent from the following detailed description. It is to be understood, however, that any method or method may be made suitable for carrying out the invention without departing from the spirit and scope of the invention, including those obtained from the following detailed description, . The appended claims, rather than these predetermined advantages, define the subject matter of the present invention. It is not necessarily the invention, but generally, any and all advantages derive from the multiple embodiments of the present invention.

The present invention generally relates to a method for diffusing a substrate into a base material. In one embodiment, a process for introducing a base material into a bath having a substrate with a catalyst is provided. A selected amount of catalyst and predetermined bath temperature are provided sufficient to lower the activation energy of the base material so that the substrate readily diffuses into the surface of the base material. Nonetheless, certain materials within the base material can inhibit diffusion of the substrate into the surface of the base material. Thus, there is further provided a selected amount of catalyst and a predetermined bath temperature sufficient to promote the leaching of such selected materials to inhibit diffusion of such substrates into such base material. The leached materials are substantially displaced by the diffused substrate.

It is to be understood that the invention includes many different aspects and features, which may be used alone and / or in combination with other aspects or features. Accordingly, this Summary does not fully identify each of these aspects or features that are now or hereafter claimed, but provides an overview of some aspects of the invention to aid in understanding the following more detailed description. The scope of the invention is not to be limited to the specific embodiments described below, but is defined by the appended claims now or hereafter.

Although the invention is susceptible of embodiment in many different forms and combinations, it is to be understood that the principles of the invention are to be considered as illustrative of the principles of the invention and are not intended to limit the broad scope of the invention. The embodiments of the invention described have particular focus.

The present invention generally relates to a method for diffusion of a substrate into a base material. In one embodiment, a process for introducing a base material into a bath having a substrate with a catalyst is provided. A selected amount of catalyst and a predetermined bath temperature sufficient to lower the activation energy of the base material are provided so that the substrate can easily diffuse into the surface of the base material. Nonetheless, certain materials within the base material can inhibit diffusion of the substrate into the surface of the base material. Thus, a selected amount of catalyst and a predetermined bath temperature sufficient to promote the leaching of such materials are further provided. The leached materials are substantially displaced by the diffused substrate.

In particular, a heated bath is used. Within about 15 to NaC0 _2, NaC0 _3, or sodium chloride in about 20 wt% (w / w%) wherein the salt bath has a (sodium chloride), sodium carbonate (sodium carbonate) and, cyanic acid sodium (sodium cyanate) with cyanic acid potassium ( potassium cyanate) is present in an amount of about 80 to about 85% by weight. A catalyzed substrate is added to the bath. Although other catalysts may be used, the catalyst may be in the form of an electrolyzed substrate. The amount of catalyst is sufficient to lower the activation energy of the base material to be treated. In addition, the amount of this selected catalyst promotes the leaching of the selected materials from the base material. In particular, the catalyst promotes leaching of selected materials that inhibit diffusion of the substrate into the base material.

The base material is impregnated in the bath with the catalyzed substrate. The temperature of the salt bath is set to a value that can lower the activation energy of the base material and promote the diffusion of the substrate into the base material. Generally, a higher temperature will promote lowering of the activation energy of the base material and promote the diffusion of the catalyzed substrate. In addition, the bath temperature is further selected to promote the leaching of such selected materials to inhibit diffusion of such substrates into such base material. To prevent any distortion or warping of the base material, the base material is impregnated in the bath for a relatively short period of time. With the reduced activation energy of the base material and the catalyst, the substrate and nitride in the bath are quickly and easily diffused into the surface of the base material. The concentration of the substrate in the bath is selected so that the substrate fully displaces the materials that have been leached from the base material during the impregnation period.

Example  One

In one particular embodiment, a 300 series stainless steel base material is treated. Stainless steels of the 300 series are generally referred to as ultralow carbon steels with austenitic properties. Typically, chromium provides its inherent corrosion resistance to stainless steel. Even so, parts of the chromium in the surface of the base material are less susceptible because titanium generally provides improved properties of being an inert, lightweight material with very high tensile strength (or toughness) and good corrosion resistance Is substituted with titanium. At the same time, chromium generally suppresses the diffusion of titanium into the base material. It is therefore desirable to diffuse titanium into the stainless steel base material using a method of promoting the leaching of chromium from the surface of the base material so that the chromium can be replaced by the substantially diffused titanium.

In one embodiment, 300 series stainless steel housings for consumer electronics products may be surface treated to improve their hardness, tensile strength and corrosion resistance. A heated bath is provided. Is present from about 15 to in the salt bath with NaC0 _2, NaC0 _3, or sodium chloride in about 20% by weight, sodium carbonate, and "a salt selected from the group consisting of cyanate and sodium cyanate, potassium, about 80 to about 85% by weight.

Catalysted titanium is added to the bath. In order to optimally reduce the activation energy of the 300 series of stainless steel base materials, promote the leaching of chromium from the stainless steel base material, and promote the diffusion of titanium into the surface of the stainless steel base material, It is preferred that from about 40 [micro] g to about 60 [micro] g of electrolyzed titanium is added to the bath so that a concentration of about 0.005% to about 0.010% of electrolytic titanium is achieved within the bath. This amount of electrolyzed titanium is desirable to replace the leached chromium from the stainless steel base material and to improve the corrosion resistance of the treated 300 series stainless steel base material. The temperature of the salt bath is heated to 590 캜 or higher, preferably about 600 캜 to about 620 캜. The electrolyzed titanium and higher temperatures catalyze the diffusion of the titanium and nitride into the base material from the bath.

The 300 series stainless steel base material is impregnated in the bath for a relatively short period of time of from about 10 minutes to about 90 minutes. To prevent any distortion or distortion of the base material, it is preferred that the stainless steel base material be impregnated in the bath heated to between about 600 [deg.] C and about 620 [deg.] C for only about 10 to about 20 minutes. With the reduced activation energy of the stainless steel base material and the leaching of chromium therefrom, the titanium in the bath quickly and easily diffuses into the surface of the base material. The titanium substantially displaces the chrome leached from the base material. Using this improved method, it was found that titanium diffuses into at least 20 microns of the surface of the 300 series stainless steel base material.

As described above, titanium has improved properties compared to chromium. Thus, the new surface of the stainless steel base material acquires these properties due to the newly diffused titanium. In particular, the surface of the stainless steel base material is more rigid without sacrificing its corrosion resistance before the surface is treated. For example, a surface hardness of about ₁₀₀ to about 1300 to 1450 HV. This method can be applied to a wide range of materials by leaching diffusion inhibiting materials (e.g., chromium) from the surface and substantially replacing them with substrates having improved properties (e.g., titanium) . In particular cases of stainless steels, lower grades and hence less expensive stainless steels (e. G., 304 series stainless steels) have been surface treated using the diffusion method of the present invention to improve their hardness, tensile strength and corrosion resistance properties .

During the titanium diffusion method of Example 1, an oxide layer may be formed on the surface of the stainless steel base material. It is therefore desirable to polish (or otherwise lightly buff) the surface of the resulting stainless steel product to achieve a desired shine and to scrape off a layer of titanium diffused into the surface of the stainless steel it is more desirable to achieve a desired gloss without scratching or otherwise removing it. In general, the resulting stainless steel product may be lightly buffed or otherwise polished using a chromium oxide polishing compound. In order to polish the surface without scraping or otherwise removing the diffused layer of titanium, the chromium oxide polishing compound has a particle size of 2 탆 or less and preferably has a particle size of about 0.5 to about 1 탆 . Particularly, the polishing compound may be a 100% cotton domet flannel type polishing wheel or a soft polishing type polishing wheel, such as a polishing wheel of a similar type commonly used for super-precision polishing wheel. The polishing wheel is typically used at a speed of from about 3000 rpm to about 5000 rpm, and preferably from about 3500 rpm to about 4500 rpm. Similarly, polished stainless steel products have a glossy surface with increased hardness and corrosion resistance due to the titanium diffusion process.

Example  2

In another particular embodiment, 400 series of stainless steel base materials may be treated. Unlike 300 series stainless steels, 400 series stainless steels have martensitic properties. The 400 series of stainless steels were also tempered at selected tempering temperatures of about 300 ° C to 530 ° C to achieve selected core hardness (eg, about 40-55 HRc). Typically, chromium provides its inherent corrosion resistance to stainless steel. Even so, it is desirable to replace a portion of chromium in the surface of the base material with titanium, since it generally provides improved properties of an inert, lightweight material with very high tensile strength (or toughness) and good corrosion resistance Do. At the same time, chromium generally suppresses the diffusion of titanium into the base material. It is therefore desirable to diffuse titanium into the stainless steel base material using a method of promoting the leaching of chromium from the surface of the base material so that the chromium can be replaced by diffused titanium.

In one embodiment, 400 series of stainless steel housings for household appliances may be surface treated to improve their hardness, tensile strength and corrosion resistance. A heated bath is provided. Is present from about 15 to in the salt bath with NaC0 _2, NaC0 _3, or sodium chloride in about 20% by weight, sodium carbonate, and "a salt selected from the group consisting of cyanate and sodium cyanate, potassium, about 80 to about 85% by weight.

Catalysted titanium is added to the bath. In order to optimally reduce the activation energies of the 400 series of stainless steel base materials, promote the leaching of chromium from the stainless steel base material, and promote the diffusion of titanium into the surface of the stainless steel base material, It is preferred that from about 40 [micro] g to about 60 [micro] g of electrolyzed titanium is added to the bath so that a concentration of about 0.005% to about 0.010% of electrolytic titanium is achieved within the bath. This amount of electrolyzed titanium is desirable to replace the leached chrome from the 400 series stainless steel base material and to improve the corrosion resistance of the treated stainless steel base material. The temperature of the salt bath is heated to 430 캜 or higher, preferably about 430 캜 to about 530 캜. The temperature of the salt bath is selected so that the original tempering conditions (e.g. tempering temperature or core hardness) of the base material are maintained. The electrolyzed titanium catalyzes the diffusion of the titanium and nitride from the bath to the base material, but the reaction rate is slower than the reaction rate of Example 1. Accordingly, for the 400 series of stainless steel, a generally increased processing time is required as compared with the 300 series of stainless steel.

The stainless steel base material is impregnated in the bath for a relatively short period of time of from about 10 minutes to about 90 minutes. To prevent any distortion or distortion of the base material, it is preferred that the stainless steel base material be impregnated in the bath heated to between about 430 [deg.] C and about 500 [deg.] C for only about 10 to about 30 minutes. With the reduced activation energy of the stainless steel base material and the leaching of chromium therefrom, the titanium in the bath is diffused into the surface of the base material. The titanium substantially displaces the chrome leached from the base material. Using this improved method, it was found that titanium diffuses into at least 15 microns of the surface of the 400 series stainless steel base material.

As described above, titanium has improved properties compared to chromium. Thus, the new surface of the stainless steel base material acquires these properties due to the newly diffused titanium. In particular, the surface of the stainless steel base material is more rigid without sacrificing its corrosion resistance before the surface is treated. For example, a surface hardness of about 900 to 1100 HV and _{100 g} . This method can be applied to a wide range of materials by leaching diffusion inhibiting materials (e.g., chromium) from the surface and replacing them with substrates having improved properties (e.g., titanium).

During the titanium diffusion method of Example 2, an oxide layer may be formed on the surface of the stainless steel base material. Thus, it is desirable to polish (or otherwise lightly buff) the resulting surface of the stainless steel product to achieve a desired gloss and to provide a predetermined, uniform thickness without scraping or otherwise removing the layer of titanium diffused into the surface of the stainless steel. It is more preferable to achieve the luster of the surface. In general, the resulting stainless steel product may be lightly buffed or otherwise polished using a chromium oxide polishing compound. In order to polish the surface without scraping or otherwise removing the diffused layer of titanium, the chromium oxide polishing compound has a particle size of 2 탆 or less and preferably has a particle size of about 0.5 to about 1 탆 . In particular, the abrasive compound may be used with a 100% facetted flange-shaped polishing wheel or a soft polishing wheel such as a similar type of polishing wheel or the like commonly used for superabrasive polishing. The polishing wheel is typically used at a speed of from about 3000 rpm to about 5000 rpm, and preferably from about 3500 rpm to about 4500 rpm. Similarly, polished stainless steel products have a glossy surface with increased hardness and corrosion resistance due to the titanium diffusion process.

Example  3

In another particular embodiment, 300 series of stainless steel base materials may be treated according to other methods. Typically, chromium provides its inherent corrosion resistance to stainless steel. Even so, it is desirable to replace a portion of chromium in the surface of the base material with titanium, since it generally provides improved properties of an inert, lightweight material with very high tensile strength (or toughness) and good corrosion resistance Do. At the same time, chromium generally suppresses the diffusion of titanium into the base material. It is therefore desirable to diffuse titanium into the stainless steel base material using a method of promoting the leaching of chromium from the surface of the base material so that the chromium can be replaced by diffused titanium.

In one embodiment, 300 series stainless steel housings for household appliances may be surface treated to improve their hardness, tensile strength and corrosion resistance. A heated bath is provided. Is present from about 15 to in the salt bath with NaC0 _2, NaC0 _3, or sodium chloride in about 20% by weight, sodium carbonate, and "a salt selected from the group consisting of cyanate and sodium cyanate, potassium, about 80 to about 85% by weight.

Catalysted titanium is added to the bath. In order to optimally reduce the activation energy of the stainless steel base material, promote the leaching of chromium from the stainless steel base material, and promote the diffusion of titanium into the surface of the stainless steel base material, It is preferred that from about 40 [micro] g to about 60 [micro] g of electrolytic titanium is added to the bath so that a concentration of 0.005% to about 0.010% of the electrolytic titanium is achieved. This amount of electrolyzed titanium is desirable to replace the leached chromium from the stainless steel base material and to improve the corrosion resistance of the treated stainless steel base material. The temperature of the salt bath is heated to 680 DEG C or higher. The electrolyzed titanium catalyzes the diffusion of the titanium and nitride into the base material from the bath.

The stainless steel base material is impregnated in the bath for a relatively short period of time of from about 10 minutes to about 30 minutes. To prevent any distortion or distortion of the base material, it is preferred that the stainless steel base material be impregnated in the bath heated to about 680 캜 to about 700 캜 for only about 10 to about 17 minutes. With the reduced activation energy of the stainless steel base material, the titanium in the bath quickly and easily diffuses into the surface of the base material. At the same time, chromium is leached from the base material. In comparison with other embodiments, the higher bath temperature in this Example 3 increases the reaction rate, which in turn increases the rate of diffusion of the titanium into the base material. However, at higher bath temperatures, the leaching of chromium from the base material is slower. As a result, more chromium is retained in the base material while more titanium diffuses resulting in a more dense diffused base material compared to other embodiments. Using this improved method, it has been found that titanium diffuses into at least 30 to 35 microns of the surface of the 300 series stainless steel base material.

Thus, the new surface of the stainless steel base material acquires the properties of newly diffused titanium and retained chromium. In particular, the surface of the stainless steel base material is more rigid without sacrificing its corrosion resistance before the surface is treated. For example, a surface hardness of about 1400-1550 HV _{100 g} .

During the titanium diffusion method of Example 3, an oxide layer may be formed on the surface of the stainless steel base material. Thus, it is desirable to polish (or otherwise lightly buff) the resulting surface of the stainless steel product to achieve a desired gloss and to provide a predetermined, uniform thickness without scraping or otherwise removing the layer of titanium diffused into the surface of the stainless steel. It is more preferable to achieve the luster of the surface. In general, the resulting stainless steel product may be lightly buffed or otherwise polished using a chromium oxide polishing compound. In order to polish the surface without scraping or otherwise removing the diffused layer of titanium, the chromium oxide polishing compound has a particle size of 2 탆 or less and preferably has a particle size of about 0.5 to about 1 탆 . In particular, the abrasive compound may be used with a 100% facetted flange-shaped polishing wheel or a soft polishing wheel such as a similar type of polishing wheel or the like commonly used for superabrasive polishing. The polishing wheel is typically used at a speed of from about 3000 rpm to about 5000 rpm, and preferably from about 3500 rpm to about 4500 rpm. Similarly, polished stainless steel products have a glossy surface with increased hardness and corrosion resistance due to the titanium diffusion process.

Although the present invention has been described with reference to certain illustrative aspects, it is to be understood that such description is not to be interpreted in a limiting sense. Rather, various changes and modifications may be made to the illustrative embodiments without departing from the true spirit, central characteristics, and aspects of the present invention, including these combinations of features individually described or claimed in this application . Moreover, it is intended that any such variations and modifications be recognized by those skilled in the art as equivalents of one or more of the following claims, and that such variations and modifications may be resorted to by those skilled in the art to the full extent permitted by law It is to be understood that the invention should be embraced within the scope of the claims.

Claims (17)

Providing a base material having at least one material that inhibits diffusion of the substrate into the base material;
Providing a salt bath comprising sodium carbonate and a salt selected from the group consisting of sodium cyanide and potassium cyanate;
Dispersing a selected amount of the substrate and a selected amount of the catalyst in the bath, wherein the selected amount of catalyst reduces leaching of the material to reduce activation energy of the base material and inhibit diffusion of the substrate into the base material Wherein the step
Heating the bath to a temperature sufficient to reduce activation energy of the base material and promote leaching of the material to inhibit diffusion of the substrate into the base material; And
Impregnating the base material in the bath for a time sufficient to cause the substrate to diffuse into the base material to substantially replace the leached material with the substrate while preventing distortion or distortion of the base material;
≪ RTI ID = 0.0 > a < / RTI > base material. Providing a base material having at least one material that inhibits diffusion of titanium into the base material;
Providing a salt bath comprising sodium carbonate and a salt selected from the group consisting of sodium cyanide and potassium cyanate;
Dispersing titanium formed by electrolysis of a selected amount of the titanium compound into the bath, wherein the selected amount of the electrolytically treated titanium reduces the activation energy of the base material and inhibits diffusion of the titanium into the base material Is sufficient to promote the leaching of the material;
Heating the bath to a temperature sufficient to reduce activation energy of the base material and promote leaching of the material to inhibit diffusion of the titanium into the base material; And
Impregnating the base material in the bath for a time sufficient to cause the titanium to diffuse into the base material to substantially replace the leached material with the titanium while preventing distortion or distortion of the base material;
≪ RTI ID = 0.0 > and / or < / RTI > Providing a 300 series stainless steel base material having chromium that inhibits diffusion of titanium into the base material;
Providing a salt bath comprising sodium carbonate, and a salt selected from the group consisting of sodium cyanide and potassium cyanate;
About 40 [micro] g to about 60 [micro] g of electrolytic titanium is dispersed in the bath so that a concentration of about 0.005% to about 0.010% of electrolytic titanium is achieved in the bath, The activation energy being low enough to promote leaching of the chromium to inhibit diffusion of the titanium into the base material;
Heating the bath to a temperature of at least 590 DEG C sufficient to reduce activation energy of the base material and promote leaching of the chrome; And
Wherein the titanium is diffused into the 300 series of stainless steel base materials to substantially displace the leached chromium with the titanium while at least about 10 to about 90 minutes to prevent distortion or distortion of the 300 series stainless steel base material Impregnating the 300 series stainless steel base material in the bath;
≪ RTI ID = 0.0 > 300 < / RTI > series of stainless steel base materials. The method of claim 3,
RTI ID = 0.0 > 600 C < / RTI > to about 620 C. The method of claim 3,
Wherein the impregnation time is from about 10 minutes to about 20 minutes. Providing a 400 series stainless steel base material having a chromium content that inhibits diffusion of titanium into the base material and further having a selected core hardness;
Providing a salt bath comprising sodium carbonate and a salt selected from the group consisting of sodium cyanide and potassium cyanate;
About 40 [micro] g to about 60 [micro] g of electrolytic titanium is dispersed in the bath so that a concentration of about 0.005% to about 0.010% of electrolytic titanium is achieved in the bath, The activation energy being low enough to promote leaching of the chromium to inhibit diffusion of the titanium into the base material;
Heating the bath to a temperature of at least 430 ° C sufficient to reduce activation energy of the base material and promote leaching of the chromium and to maintain the original tempering conditions of the 400 series of base materials; And
Wherein the titanium is diffused into the 400 series stainless steel base material to substantially displace the leached chromium with the titanium while at least about 10 to about 90 minutes to prevent distortion or distortion of the 400 series stainless steel base material Impregnating the 400 series stainless steel base material in the bath;
≪ RTI ID = 0.0 > 400 < / RTI > series of stainless steel base materials. The method according to claim 6,
RTI ID = 0.0 > 500 C < / RTI > The method according to claim 6,
Wherein the impregnation time is from about 10 minutes to about 30 minutes. Providing a 300 series stainless steel base material having a chromium content that inhibits diffusion of titanium into the base material and further having a selected core hardness;
Providing a salt bath comprising sodium carbonate and a salt selected from the group consisting of sodium cyanide and potassium cyanate;
About 40 [micro] g to about 60 [micro] g of electrolytic titanium is dispersed in the bath so that a concentration of about 0.005% to about 0.010% of electrolytic titanium is achieved in the bath, The activation energy being low enough to promote leaching of the chromium to inhibit diffusion of the titanium into the base material;
Heating the bath to a temperature of at least 680 DEG C sufficient to reduce activation energy of the base material and promote leaching of the chrome; And
Wherein the titanium is diffused into the 300 series stainless steel base material to substantially displace the leached chromium with the titanium while at least about 10 to about 30 minutes to prevent distortion or distortion of the 300 series stainless steel base material Impregnating the 300 series stainless steel base material in the bath;
≪ RTI ID = 0.0 > 300 < / RTI > series of stainless steel base materials. 10. The method of claim 9,
RTI ID = 0.0 > 700 C < / RTI > 10. The method of claim 9,
Wherein the impregnation time is from about 10 minutes to about 30 minutes. Providing a stainless steel base material having a chromium content that inhibits diffusion of titanium into the base material, and further having a selected core hardness;
Providing a salt bath comprising sodium carbonate and a salt selected from the group consisting of sodium cyanide and potassium cyanate;
Dispersing in the bath of electrolytic titanium sufficient to reduce activation energy of the base material and promote leaching of the chromium that inhibits diffusion of the titanium into the base material;
Heating the bath to a temperature sufficient to reduce activation energy of the base material and promote leaching of the chromium;
Impregnating the stainless steel base material into the bath so that the titanium diffuses into the stainless steel base material to substantially displace the leached chrome with the titanium while preventing distortion or distortion of the stainless steel base material ; And
Polishing the base material after diffusion of the titanium;
And diffusing the titanium and nitride into a series of stainless steel base materials, wherein the titanium and the nitride are polished. 13. The method of claim 12,
Wherein the base material is polished using a chromium oxide polishing compound. 14. The method of claim 13,
Wherein the chromium oxide polishing compound has a particle size of 2 [mu] m or less. 14. The method of claim 13,
Wherein the chromium oxide polishing compound has a particle size of from about 0.5 to about 1 mu m. 13. The method of claim 12,
Wherein the base material is polished using a plano-dimetron flannel-shaped polishing wheel at a polishing rate of from about 3000 rpm to about 5000 rpm. 17. The method of claim 16,
Wherein the polishing rate is from about 3500 rpm to about 4500 rpm.