Case hardening - Revision history

Dnevil: /* Procedure */

2020-04-01T13:17:26Z

Procedure

← Older revision		Revision as of 08:17, 1 April 2020
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	: Two counterpoints to add:		: Two counterpoints to add:
	:: 1. If you are having steel laser cut, due to the Heat Affected Zone, you already have a localized case-hardened teeth on the quadrant.		:: 1. If you are having steel laser cut, due to the Heat Affected Zone, you already have a localized case-hardened teeth on the quadrant.
	:: 2. If you make the parts out of a heat treatable alloy (like 4140) then carburizing is unnecessary. Just heat and quench. Draw the temper if desired.		:: 2. If you make the parts out of a heat treatable alloy (like [[AISI 4140]]) then carburizing is unnecessary. Just heat and quench. Draw the temper if desired.

	== External Links ==		== External Links ==

Dnevil: /* Procedure */

2020-04-01T13:12:18Z

Procedure

← Older revision		Revision as of 08:12, 1 April 2020
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	File:AndrewMatthews case hardengin Facebook 20200401-3.jpg\|The arm after polishing on the surface table with some wet and dry.		File:AndrewMatthews case hardengin Facebook 20200401-3.jpg\|The arm after polishing on the surface table with some wet and dry.
	</gallery>		</gallery>

			Adam Wright posted on <i>Facebook</i>, 1 April 2020:

			: Two counterpoints to add:
			:: 1. If you are having steel laser cut, due to the Heat Affected Zone, you already have a localized case-hardened teeth on the quadrant.
			:: 2. If you make the parts out of a heat treatable alloy (like 4140) then carburizing is unnecessary. Just heat and quench. Draw the temper if desired.

	== External Links ==		== External Links ==

Dnevil: /* Case Hardening */

2020-04-01T13:08:29Z

Case Hardening

← Older revision		Revision as of 08:08, 1 April 2020
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	See [[Hardening and Tempering Colors]].		See [[Hardening and Tempering Colors]].

	== ~~Case Hardening~~ ==		== Procedure ==

	[https://en.wikipedia.org/wiki/Case-hardening Case-hardening] or surface hardening is the process of hardening the surface of a metal object while allowing the metal deeper underneath to remain soft, thus forming a thin layer of harder metal (called the "case") at the surface. For iron or steel with low carbon content, which has poor to no hardenability of its own, the case-hardening process involves infusing additional carbon or nitrogen into the surface layer. Case-hardening is usually done after the part has been formed into its final shape

	[[Jim Kreider]] posted the following <i>Facebook</i>, 1 April 2020:		[[Jim Kreider]] posted the following <i>Facebook</i>, 1 April 2020:
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	:: When case hardening you should wear gas welding glasses. First, heat the work piece to dull red heat. Then immerse the work piece in <i>Kasenit</i>, or <i>Cherry Red</i>. The case hardening powder will then stick to the work piece. Then bake the part at red heat for a couple minutes with the oxygen acetylene torch. You may have to re coat it. As the part will incandesce brightly while being heated, you should do this while looking through the dark glasses. When doing this have the glasses hanging on the end of your nose so that when you take the torch away from the work piece, you can look over the top of the glasses and check the heat. Be careful not to overheat the part. Re coat the part with the case hardening powder and repeat the baking process for another minute or so. Then while the part is still at red heat quench it in cold water. Its hard to judge the heat of the part with the dark glasses on. So that’s the reason for having them down on your nose so you can look over them when you take the torch away. You should also have a nice finish on the part before hardening. After hardening you should check the part with a file. The file should glide over the part without cutting. This is a very handy process and I often use it on the pins in a throttle linkage. With phosphor bronze bushing and carefully fitted hardened pins a throttle linkage will have no lost motion and will remain that way.		:: When case hardening you should wear gas welding glasses. First, heat the work piece to dull red heat. Then immerse the work piece in <i>Kasenit</i>, or <i>Cherry Red</i>. The case hardening powder will then stick to the work piece. Then bake the part at red heat for a couple minutes with the oxygen acetylene torch. You may have to re coat it. As the part will incandesce brightly while being heated, you should do this while looking through the dark glasses. When doing this have the glasses hanging on the end of your nose so that when you take the torch away from the work piece, you can look over the top of the glasses and check the heat. Be careful not to overheat the part. Re coat the part with the case hardening powder and repeat the baking process for another minute or so. Then while the part is still at red heat quench it in cold water. Its hard to judge the heat of the part with the dark glasses on. So that’s the reason for having them down on your nose so you can look over them when you take the torch away. You should also have a nice finish on the part before hardening. After hardening you should check the part with a file. The file should glide over the part without cutting. This is a very handy process and I often use it on the pins in a throttle linkage. With phosphor bronze bushing and carefully fitted hardened pins a throttle linkage will have no lost motion and will remain that way.

			Andrew Matthews posted on <i>Facebook</i>, 1 April 2020:

			: For smallish parts I find the MAPP gas flame an ideal temperature for case hardening, keeping the part nice and hot without burning it.

			<gallery widths=300px heights=300px perrow=2>
			File:AndrewMatthews case hardengin Facebook 20200401-1.jpg\|Here I am casehardening a mechanical lubricator driving arm, being held with my cheap sacrificial set of long nose pliers.
			File:AndrewMatthews case hardengin Facebook 20200401-2.jpg\|The arm after quenching you can see the grey mottled appearance, generally a good sign it has worked well when all the coating has been blown off by the boiling water during quenching.
			File:AndrewMatthews case hardengin Facebook 20200401-3.jpg\|The arm after polishing on the surface table with some wet and dry.
			</gallery>

	== External Links ==		== External Links ==

Dnevil: /* Procedure */

2020-04-01T12:58:30Z

Procedure

← Older revision		Revision as of 07:58, 1 April 2020
Line 22:		Line 22:
	See [[Hardening and Tempering Colors]].		See [[Hardening and Tempering Colors]].

	== ~~Procedure~~ ==		== Case Hardening ==

			[https://en.wikipedia.org/wiki/Case-hardening Case-hardening] or surface hardening is the process of hardening the surface of a metal object while allowing the metal deeper underneath to remain soft, thus forming a thin layer of harder metal (called the "case") at the surface. For iron or steel with low carbon content, which has poor to no hardenability of its own, the case-hardening process involves infusing additional carbon or nitrogen into the surface layer. Case-hardening is usually done after the part has been formed into its final shape

	[[Jim Kreider]] posted the following <i>Facebook</i>, 1 April 2020:		[[Jim Kreider]] posted the following <i>Facebook</i>, 1 April 2020:

Dnevil: /* Tempering */

2020-04-01T12:56:20Z

Tempering

← Older revision		Revision as of 07:56, 1 April 2020
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	See [[Hardening and Tempering Colors]].		See [[Hardening and Tempering Colors]].

			== Procedure ==

			[[Jim Kreider]] posted the following <i>Facebook</i>, 1 April 2020:

			: Some of the parts that you will make while building a live steam locomotive will be made out of ordinary soft carbon steel. They will require at least a case-hardening treatment before they are applied to the locomotive to make sure that they will wear well during use.

			: One part that comes to mind is the throttle lever quadrant. I had these parts laser cut. With all those little teeth on the quadrant the laser had to cut maybe three teeth, go to another section of the quadrant, and then come back where it left off to avoid overheating and burning off those small teeth in a given area.

			: A process to case harden that I have used in the past with success is to use “case-hardening powder”

			: [[Jack Bodenmann]] describes the process quite well;

			:: When case hardening you should wear gas welding glasses. First, heat the work piece to dull red heat. Then immerse the work piece in <i>Kasenit</i>, or <i>Cherry Red</i>. The case hardening powder will then stick to the work piece. Then bake the part at red heat for a couple minutes with the oxygen acetylene torch. You may have to re coat it. As the part will incandesce brightly while being heated, you should do this while looking through the dark glasses. When doing this have the glasses hanging on the end of your nose so that when you take the torch away from the work piece, you can look over the top of the glasses and check the heat. Be careful not to overheat the part. Re coat the part with the case hardening powder and repeat the baking process for another minute or so. Then while the part is still at red heat quench it in cold water. Its hard to judge the heat of the part with the dark glasses on. So that’s the reason for having them down on your nose so you can look over them when you take the torch away. You should also have a nice finish on the part before hardening. After hardening you should check the part with a file. The file should glide over the part without cutting. This is a very handy process and I often use it on the pins in a throttle linkage. With phosphor bronze bushing and carefully fitted hardened pins a throttle linkage will have no lost motion and will remain that way.

	== External Links ==		== External Links ==

Dnevil: /* External Links */

2016-07-08T18:45:08Z

External Links

← Older revision		Revision as of 13:45, 8 July 2016
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	** [http://www.midwayusa.com/product/119479/cherry-red-surface-hardening-compound-1-lb Cherry Red, 1 pound, <i>Midway USA</i>]		** [http://www.midwayusa.com/product/119479/cherry-red-surface-hardening-compound-1-lb Cherry Red, 1 pound, <i>Midway USA</i>]
	* [http://www.technologystudent.com/equip1/heat2.htm "Case Hardening of Mild Steel"]		* [http://www.technologystudent.com/equip1/heat2.htm "Case Hardening of Mild Steel"]
			* [http://www.chaski.org/homemachinist/viewtopic.php?f=8&t=76338 "KASENIT Case Hardener", <i>Chaski.org</i>]

Dnevil: /* External Links */

2015-01-15T04:40:52Z

External Links

← Older revision		Revision as of 23:40, 14 January 2015
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	* [http://www.rosemill.com/category_s/46.htm Rose Mill Cherry Red carburizing case hardener]		* [http://www.rosemill.com/category_s/46.htm Rose Mill Cherry Red carburizing case hardener]
	** [http://www.midwayusa.com/product/119479/cherry-red-surface-hardening-compound-1-lb Cherry Red, 1 pound, <i>Midway USA</i>]		** [http://www.midwayusa.com/product/119479/cherry-red-surface-hardening-compound-1-lb Cherry Red, 1 pound, <i>Midway USA</i>]
			* [http://www.technologystudent.com/equip1/heat2.htm "Case Hardening of Mild Steel"]

Dnevil: /* External Links */

2015-01-15T04:34:48Z

External Links

← Older revision		Revision as of 23:34, 14 January 2015
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	* [http://en.wikipedia.org/wiki/Case_hardening "Case hardening", <i>Wikipedia</i>]		* [http://en.wikipedia.org/wiki/Case_hardening "Case hardening", <i>Wikipedia</i>]
	* [http://en.wikipedia.org/wiki/Tempering_%28metallurgy%29 "Tempering", <i>Wikipedia</i>]		* [http://en.wikipedia.org/wiki/Tempering_%28metallurgy%29 "Tempering", <i>Wikipedia</i>]
			* [http://www.rosemill.com/category_s/46.htm Rose Mill Cherry Red carburizing case hardener]
			** [http://www.midwayusa.com/product/119479/cherry-red-surface-hardening-compound-1-lb Cherry Red, 1 pound, <i>Midway USA</i>]

Dnevil: Created page with "Category:Definitions Category:Construction Case hardening or surface hardening is the process of hardening the surface of a metal object while allowing the metal ..."

2015-01-15T04:30:10Z

Created page with "Category:Definitions Category:Construction Case hardening or surface hardening is the process of hardening the surface of a metal object while allowing the metal ..."

New page

[[Category:Definitions]]
[[Category:Construction]]

[[Case hardening]] or surface hardening is the process of hardening the surface of a metal object while allowing the metal deeper underneath to remain soft, thus forming a thin layer of harder metal (called the "case") at the surface. For iron or steel with low carbon content, which has poor to no hardenability of its own, the case hardening process involves infusing additional carbon into the case. Case hardening is usually done after the part has been formed into its final shape, but can also be done to increase the hardening element content of bars to be used in a pattern welding or similar process. The term face hardening is also used to describe this technique, when discussing modern armour.

Because hardened metal is usually more brittle than softer metal, through-hardening (that is, hardening the metal uniformly throughout the piece) is not always a suitable choice for applications where the metal part is subject to certain kinds of stress. In such applications, case hardening can provide a part that will not fracture (because of the soft core that can absorb stresses without cracking) but also provides adequate wear resistance on the surface.

== Carburizing ==

Carburizing is a process used to case harden steel with a carbon content between 0.1 and 0.3 wt% C. In this process steel is introduced to a carbon rich environment and elevated temperatures for a certain amount of time, and then quenched so that the carbon is locked in the structure; one of the simpler procedures is repeatedly to heat a part with an acetylene torch set with a fuel-rich flame and quench it in a carbon-rich fluid such as oil.

Carburization is a diffusion-controlled process, so the longer the steel is held in the carbon-rich environment the greater the carbon penetration will be and the higher the carbon content. The carburized section will have a carbon content high enough that it can be hardened again through flame or induction hardening.

It is possible to carburize only a portion of a part, either by protecting the rest by a process such as copper plating, or by applying a carburizing medium to only a section of the part.

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, while the more recent types such as Cherry Red do not.

== Tempering ==

Tempering is a process of heat treating, which is used to increase the toughness of iron-based alloys. Tempering is usually performed after hardening, to reduce some of the excess hardness, and is done by heating the metal to some temperature below the critical point for a certain period of time, then allowing it to cool in still air. The exact temperature determines the amount of hardness removed, and depends on both the specific composition of the alloy and on the desired properties in the finished product. For instance, very hard tools are often tempered at low temperatures, while springs are tempered to much higher temperatures. In glass, tempering is performed by heating the glass and then quickly cooling the surface, increasing the toughness.

See [[Hardening and Tempering Colors]].

== External Links ==

* [http://en.wikipedia.org/wiki/Case_hardening "Case hardening", Wikipedia]
* [http://en.wikipedia.org/wiki/Tempering_%28metallurgy%29 "Tempering", Wikipedia]