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  • #31
    Evan.

    Have no problem with chlorine at the 5% level; don’t like chlorine gas or anything above 7%.

    50% Chlorine…You’re e not talking about table salt are you? Sodium CHLORIDE?

    There is a difference between Chlorine and Chloride. Chlorine is an element, it is a strong oxidizer, Chloride ions are essentially non-reactive.

    And the fact that a certain product is found in foods,…. Doesn’t convince me as being safe. Read several DOD reports about aspartame (Equal, NutraSweet) breaking down into some very nasty compounds when heated.

    So who here can tell me what Sodium the break down components are of Sodium ferrocyanide when heated to 1500 deg F?
    Mike Hunter

    www.mikehunterrestorations.com

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    • #32
      Originally posted by lazlo
      Kasenit is a common carburizing compound. Like all carburizing processes, Kasenit must be applied above the austentizing temperature: 1500 - 1800F.

      Case Hardening

      http://en.wikipedia.org/wiki/Case_hardening

      Modern use

      The term case hardening is derived from the practicalities of the carburization process itself, which is essentially the same as the ancient process. The steel work piece is placed inside a case packed tight with a carbon-based case hardening compound. This is collectively known as a carburizing pack. The pack is put inside a hot furnace for a variable length of time. Time and temperature determines how deep into the surface the hardening extends. However, the depth of hardening is ultimately limited by the inability of carbon to diffuse deeply into solid steel, and a typical depth of surface hardening with this method is up to 1.5 mm. Other techniques are also used in modern carburizing, such as heating in a carbon rich atmosphere. Small items may be case hardened by repeated heating with a torch and quenching in a carbon rich medium, such as the commercial products Kasenit / Casenite or "Cherry Red". Older formulations of these compounds contain potentially toxic cyanide compounds, such as ferrocyanide compounds, while the more recent types such as Cherry Red do not.[1][2]
      "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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      • #33
        CASE-HARDENING MATERIALS-carbonitriding-nitrocarburizing
        Materials for adding carbon and/or other elements to the surface of low-carbon or medium-carbon steels or to iron so that upon quenching a hardened case is obtained, with the center of the steel remaining soft and ductile. The material may be plain charcoal, raw bone, or mixtures marketed as carburizing compounds. A common mixture is about 60% charcoal and 40 barium carbonate. The latter decomposes, giving carbon dioxide, which is reduced to carbon monoxide in contact with the hot charcoal. If charcoal is used alone, action is slow and spotty. Coal or coke can be used, but action is slow, and the sulfur in these materials is detrimental. Salt is sometimes added to aid the carburizing action. By proper selection of the carburizing material, the carbon content may be varied in the steel from 0.80 to 1.20%. The carburizing temperature for carbon steels typically ranges from 1550 to 1750°F (850 to 950°C) but may be as low as 1450°F (790°C) or as high as 2000°F (1095°C). The articles to be car-burized for case hardening are packed in metallic boxes for heating in a furnace, and the process is called pack hardening, as distinct from the older method of burying the red-hot metal in charcoal.


        Steels are also case-hardened by the diffusion of carbon and nitrogen, called carbonitriding, or nitrogen alone, called nitriding. Carbonitriding, also known as dry cyaniding, gas cyaniding, liquid cyaniding, nicarbing, and nitrocarburizing, involves the diffusion of carbon and nitrogen into the case. Nitriding also may be done by gas or liquid methods. In carbonitriding, the steel may be exposed to a carrier gas containing carbon and as much as 10% ammonia, the nitrogen source, or a molten cyanide salt, which provides both elements. Ammonia, from gaseous or liquid salts, is also the nitrogen source for nitriding. Although low- and medium-carbon steels are commonly used for carburizing and carbonitriding, nitrid-ing is usually applied only to alloy steels containing nitride-forming elements, such as aluminum, chromium, molybdenum, and vanadium. In ion nitriding, or glow-discharge nitriding, electric current is used to ionize low-pressure nitrogen gas. The ions are accelerated to the workpiece by the electric potential, and the work-piece is heated by the impinging ions, obviating an additional heat source. All three principal case-hardening methods provide a hard, wear-resistant case. Carburizing, however, which gives the greater case depth, provides the best contact-load capacity. Nitriding provides the best dimensional control, and carbonitriding is intermediate in this respect.
        The principal liquid-carburizing material is sodium cyanide, which is melted in a pot that the articles are dipped in, or the cyanide is rubbed on the hot steel. Cyanide hardening gives an extremely hard but superficial case. Nitrogen as well as carbon is added to the steel by this process. Gases rich in carbon, such as methane, may also be used for carburizing, by passing the gas through the box in the furnace. When ammonia gas is used to impart nitrogen to the steel, the process is not called carburizing but is referred to as nitriding. Tufftriding, of Degussa AG of Germany, is a nitriding process using molten potassium cyanate with a small amount of sodium ferro-cyanide in titanium-lined melting pots.Case-hardening compounds are marketed under a wide variety of trade names. These may have a base of hardwood charcoal or of charred bone, with sodium carbonate, barium carbonate, or calcium carbonate. Char is a carburizing material in which the particles of coal-tar carbon are surrounded by an activator and covered with a carbon coating. Accelerated Salt WS, of Du Pont, for heat-treating baths, has a content of 66% sodium cyanide, with graphite to minimize fuming and radiation losses. For selective case hardening on steel parts, a stiff paste of carburizing material may be applied to the surfaces where a carbon impregnation is desired. Carburit is a car-burizing paste of this kind. Aerocarb and Aerocase, of American Cyanamid Co., are mixtures of sodium and potassium nitrates and nitrides for use in carburizing baths at a temperature up to 1850°F (1010°C).
        Sodium cyanide is used in most industrial carbonitriding because it is cheaper than sodium ferrocyanide. Either salt has the same action since they both contain nitrogen. Sodium cyanide is NaCN and Sodium ferrocyanide is Na4Fe(CN)6.


        http://dictionary.mechanicalengineer...rburizing.html
        Last edited by Evan; 04-17-2009, 07:17 PM.
        Free software for calculating bolt circles and similar: Click Here

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        • #34
          There is a difference between Chlorine and Chloride. Chlorine is an element, it is a strong oxidizer, Chloride ions are essentially non-reactive.
          No there isn't any difference other than the fact it is reacted with another element, the same as the Carbon and Nitrogen in a cyanide. It's the carbon-nitrogen bond that makes a cyanide a cyanide regardless of whatever else it is combined with. The chlorine in salt is elemental chlorine and can easily be released by electrolysis of salt water during derusting for example.

          When the CN is also bonded with iron it is inert enough to eat, which you do if you consume commercial table salt. Sodium cyanide is a food grade additive used to prevent table salt from caking.
          Free software for calculating bolt circles and similar: Click Here

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          • #35
            Originally posted by Evan
            Sodium cyanide is used in most industrial carbonitriding because it is cheaper than sodium ferrocyanide.

            Sodium cyanide,
            NaCN, which is used in molten salt baths for carburizing, is a completely different chemical than sodium ferrocyanide, Na4Fe(CN)6, which is the active ingredient in Kasenit.

            Sodium cyanide is highly toxic.

            Sodium ferrocyanide is complete inert, and used as a food grade anti-caking agent, and is the pigment in Prussian Blue.



            Sodium cyanide is the inorganic compound with the formula NaCN. This highly toxic colourless salt is used mainly in gold mining but has other niche applications. It is the conjugate base of the weak acid hydrogen cyanide.

            Sodium ferrocyanide, is a coordination compound of formula Na4Fe(CN)6 which forms semi-transparent yellow crystals at room temperature, and which decomposes at its boiling point. Despite the presence of the cyanide ligands, sodium ferrocyanide is not especially toxic because the cyanides are tightly bound to the metal, although it can react with acid or photodecompose to release hydrogen cyanide gas.

            As yellow prussiate of soda, it is added to road and food grade salt as an anticaking agent. When combined with iron, it converts to a deep blue pigment which is the main component of Prussian blue. In photography it is used for bleaching, toning and fixing. It is used as a stabilizer for the coating on welding rods. In the petroleum industry it is used for removal of mercaptans.
            Last edited by lazlo; 04-18-2009, 12:08 AM.
            "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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            • #36
              Everything you wrote and quoted is true at room temperature.

              So what?

              You obviously aren't even reading what I have posted. Good night Robert.
              Free software for calculating bolt circles and similar: Click Here

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              • #37
                Originally posted by Evan View Post
                Sodium cyanide is a food grade additive used to prevent table salt from caking.
                I very much doubt it, certainly not in Australia. Perhaps the KGB used it long ago, now it seems they use nerve agents according to newspaper reports.
                Rob.

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                • #38
                  Originally posted by Ropetangler View Post
                  I very much doubt it, certainly not in Australia. Perhaps the KGB used it long ago, now it seems they use nerve agents according to newspaper reports.
                  Rob.
                  Yellow prussiate of soda (a.k.a. sodium ferrocyanide) is the anti-caking agent added to table salt.
                  Mike
                  WI/IL border, USA

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                  • #39
                    someone please contact Evan so this can go on for 500 posts
                    .

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                    • #40
                      Originally posted by MichaelP View Post
                      Yellow prussiate of soda (a.k.a. sodium ferrocyanide) is the anti-caking agent added to table salt.
                      Fortunately, that is slightly different from "Sodium cyanide".

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                      • #41
                        I believe this is the stuff you want for case hardening at any rate:
                        https://www.ebay.de/sch/i.html?_from...exacyanoferrat

                        A source for those in europe. Known as "blood lye salt" in swedish.

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                        • #42
                          I still have a can of the old Kasenit. Must be worth a couple of Bit Coins by now.

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                          • #43
                            People, look at the dates before posting. This thread is 9 years old.

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                            • #44
                              Originally posted by Yondering View Post
                              People, look at the dates before posting. This thread is 9 years old.
                              It WAS 9 years old.....
                              1601

                              Keep eye on ball.
                              Hashim Khan

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                              • #45
                                Originally posted by Yondering View Post
                                People, look at the dates before posting. This thread is 9 years old.
                                Look at the dates, but don't let the date keep you from posting.

                                There's still a bit of 2009 home shop technology that's not completely obsolete yet.

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