Comments for bainite http://bainite.wordpress.com it's not pearlite or martensite. Thu, 05 Nov 2009 22:11:27 +0000 http://wordpress.com/ hourly 1 Comment on Carbon in steels – near equilibrium structures. by Mathew Peet http://bainite.wordpress.com/2006/04/13/carbon-in-steels-near-equilibrium-structures/#comment-10063 Mathew Peet Thu, 05 Nov 2009 22:11:27 +0000 https://bainite.wordpress.com/2006/04/13/carbon-in-steels-near-equilibrium-structures/#comment-10063 Dear Bruce, I wouldn't say that this makes them non-useful. However if we want to avoid the low toughness we need to avoid forming these networks. I believe I read that this can be done by deformation at high temperature, if this can be done to cause the cementite as to be present as spheroids. High deformation will cause large nucleation rate of cementite and if there is enough sites this will prevent the formation of the cementite films on the grain boundaries. Unfortunately I can't remember the reference for the above. I think there may be by a paper with David Edmonds of the University of Leeds as one of the authors. Alternatives which might work in theory would be to try to refine as much as possible the austenite grain size or to try to allow the cementite to globalise, i.e. by show heating up to the austenitisation temperature, which would not be sufficient to completely dissolve the cementite. I don't believe that silicon will suppress the formation of cementite at high temperatures, it may in fact promote the formation of cementite (at high temperatures). This can be shown by thermodynamic calculations. Fast cooling from fully austenite may be one way to avoid cementite formation (or at least growth of large particles). However formation on g.b.s will be very fast. Another way is very short austenitising heat treatments with rapid heating. This can be seen in the flash bainite process (http://www.bainitesteel.com/) you might find a paper by Suersh Babu that deals with this. Sorry I don't know the proper references about this I can only give a clue for the time being. If you have luxury of changing the composition you could try shifting the eutectoid to higher carbon contents. Of other alloying to lower the cementite stability (this usually means removing alloying elements). Dear Bruce, I wouldn’t say that this makes them non-useful. However if we want to avoid the low toughness we need to avoid forming these networks. I believe I read that this can be done by deformation at high temperature, if this can be done to cause the cementite as to be present as spheroids. High deformation will cause large nucleation rate of cementite and if there is enough sites this will prevent the formation of the cementite films on the grain boundaries.

Unfortunately I can’t remember the reference for the above. I think there may be by a paper with David Edmonds of the University of Leeds as one of the authors.

Alternatives which might work in theory would be to try to refine as much as possible the austenite grain size or to try to allow the cementite to globalise, i.e. by show heating up to the austenitisation temperature, which would not be sufficient to completely dissolve the cementite.

I don’t believe that silicon will suppress the formation of cementite at high temperatures, it may in fact promote the formation of cementite (at high temperatures).

This can be shown by thermodynamic calculations.

Fast cooling from fully austenite may be one way to avoid cementite formation (or at least growth of large particles). However formation on g.b.s will be very fast.

Another way is very short austenitising heat treatments with rapid heating. This can be seen in the flash bainite process (http://www.bainitesteel.com/) you might find a paper by Suersh Babu that deals with this.

Sorry I don’t know the proper references about this I can only give a clue for the time being.

If you have luxury of changing the composition you could try shifting the eutectoid to higher carbon contents. Of other alloying to lower the cementite stability (this usually means removing alloying elements).

]]> Comment on Carbon in steels – near equilibrium structures. by Bruce Bramfitt http://bainite.wordpress.com/2006/04/13/carbon-in-steels-near-equilibrium-structures/#comment-10062 Bruce Bramfitt Thu, 05 Nov 2009 14:10:55 +0000 https://bainite.wordpress.com/2006/04/13/carbon-in-steels-near-equilibrium-structures/#comment-10062 Hypereutectoid steels are not useful due to the formation of brittle proeutectoid cementite networks that form at the prior austenite grain boundaries. However, adding high levels of silicon can suppress the formation of these networks. How does silicon do this, i.e., what is the mechanism? Is there a carbon- silicon ratio that can tell me how much silicon to add to the steel to minimize these continuous networks? Hypereutectoid steels are not useful due to the formation of brittle proeutectoid cementite networks that form at the prior austenite grain boundaries. However, adding high levels of silicon can suppress the formation of these networks. How does silicon do this, i.e., what is the mechanism? Is there a carbon- silicon ratio that can tell me how much silicon to add to the steel to minimize these continuous networks?

]]> Comment on Pret A Manger Against Science? by Phil Wilson http://bainite.wordpress.com/2009/09/09/pret-a-manger-against-science/#comment-10060 Phil Wilson Mon, 02 Nov 2009 21:37:58 +0000 http://bainite.wordpress.com/?p=557#comment-10060 I always like it when a company claims that their product "contains no chemicals" what, really? no chemicals? at all? I hope they're packing that vacuum carefully. I always like it when a company claims that their product “contains no chemicals”

what, really? no chemicals? at all? I hope they’re packing that vacuum carefully.

]]> Comment on Some effects of Alloying elements in Steel by Mathew http://bainite.wordpress.com/2006/04/21/some-effects-of-alloying-elements-in-steel/#comment-10058 Mathew Thu, 22 Oct 2009 14:06:34 +0000 https://bainite.wordpress.com/2006/04/21/some-effects-of-alloying-elements-in-steel/#comment-10058 if you search "saph400 properties" you can find some information like composition, UTS=> 400 MPa, yield strength, elongation, etc, from different suppliers. if you search “saph400 properties” you can find some information like composition, UTS=> 400 MPa, yield strength, elongation, etc, from different suppliers.

]]> Comment on Some effects of Alloying elements in Steel by Deden http://bainite.wordpress.com/2006/04/21/some-effects-of-alloying-elements-in-steel/#comment-10056 Deden Thu, 22 Oct 2009 06:05:39 +0000 https://bainite.wordpress.com/2006/04/21/some-effects-of-alloying-elements-in-steel/#comment-10056 i was effort to searching the web but i didn't found SAPH 400 steel properties... but i found using the SAPH 400. i was effort to searching the web but i didn’t found SAPH 400 steel properties… but i found using the SAPH 400.

]]> Comment on Some effects of Alloying elements in Steel by mathew http://bainite.wordpress.com/2006/04/21/some-effects-of-alloying-elements-in-steel/#comment-10055 mathew Wed, 21 Oct 2009 11:32:15 +0000 https://bainite.wordpress.com/2006/04/21/some-effects-of-alloying-elements-in-steel/#comment-10055 I don't know about it, you should try seaching the web, or supplier literature for that grade. I don’t know about it, you should try seaching the web, or supplier literature for that grade.

]]> Comment on Some effects of Alloying elements in Steel by Deden http://bainite.wordpress.com/2006/04/21/some-effects-of-alloying-elements-in-steel/#comment-10054 Deden Wed, 21 Oct 2009 04:44:17 +0000 https://bainite.wordpress.com/2006/04/21/some-effects-of-alloying-elements-in-steel/#comment-10054 Dear All, Hi, please give me information about SAPH 400 steel properties. thanxxxx b4 Dear All,

Hi, please give me information about SAPH 400 steel properties.

thanxxxx b4

]]> Comment on How to make a diamond by ajayi http://bainite.wordpress.com/2006/09/29/how-to-make-a-diamond/#comment-10051 ajayi Sat, 26 Sep 2009 02:26:23 +0000 http://bainite.wordpress.com/2006/09/29/how-to-make-a-diamond/#comment-10051 pls how do i get the wafers of synthetic or diamon seed silver???? or how do i make it pls how do i get the wafers of synthetic or diamon seed silver???? or how do i make it

]]> Comment on Some effects of Alloying elements in Steel by Vik http://bainite.wordpress.com/2006/04/21/some-effects-of-alloying-elements-in-steel/#comment-10047 Vik Tue, 15 Sep 2009 20:08:12 +0000 https://bainite.wordpress.com/2006/04/21/some-effects-of-alloying-elements-in-steel/#comment-10047 Hi, I am curious about increase Aluminum Solubility in Austenite. Would you have any references related to Alumnium Solubility Vs Carbon %wt. Thank you. Vik Hi,

I am curious about increase Aluminum Solubility in Austenite.
Would you have any references related to Alumnium Solubility Vs Carbon %wt.

Thank you.
Vik

]]> Comment on Pret A Manger Against Science? by Rob Oxspring http://bainite.wordpress.com/2009/09/09/pret-a-manger-against-science/#comment-10045 Rob Oxspring Wed, 09 Sep 2009 14:53:13 +0000 http://bainite.wordpress.com/?p=557#comment-10045 Well said both! Well said both!

]]> Comment on Pret A Manger Against Science? by AZ http://bainite.wordpress.com/2009/09/09/pret-a-manger-against-science/#comment-10044 AZ Wed, 09 Sep 2009 11:00:10 +0000 http://bainite.wordpress.com/?p=557#comment-10044 Ditto. The natural=good argument is pathetic. As if there are no natural poisons. As if there are no major dangers in raw, unprocessed food. Pathetic - just pathetic. Ditto.
The natural=good argument is pathetic.
As if there are no natural poisons.
As if there are no major dangers in raw, unprocessed food.
Pathetic – just pathetic.

]]> Comment on How do trees raise water? by Andrew K Fletcher http://bainite.wordpress.com/2006/05/06/how-do-trees-raise-water/#comment-10043 Andrew K Fletcher Mon, 31 Aug 2009 12:04:20 +0000 https://bainite.wordpress.com/2006/05/06/how-do-trees-raise-water/#comment-10043 Titre du document / Document title Modeling xylem and phloem water flows in trees according to cohesion theory and münch hypothesis Auteur(s) / Author(s) HÖLTTÄ T. (1) ; VESALA T. (1) ; SEVANTO S. (1) ; PERÄMÄKI M. (2) ; NIKINMAA E. (2) ; Affiliation(s) du ou des auteurs / Author(s) Affiliation(s) (1) Department of Physical Sciences, University of Helsinki, P.O. Box 64, 00014, FINLANDE (2) Department of Forest Ecology, University of Helsinki, P.O. Box 24, 00014, FINLANDE Résumé / Abstract Water and solute flows in the coupled system of xylem and phloem were modeled together with predictions for xylem and whole stem diameter changes. With the model we could produce water circulation between xylem and phloem as presented by the Münch hypothesis. Viscosity was modeled as an explicit function of solute concentration and this was found to vary the resistance of the phloem sap flow by many orders of magnitude in the possible physiological range of sap concentrations. Also, the sensitivity of the predicted phloem translocation to changes in the boundary conditions and parameters such as sugar loading, transpiration, and hydraulic conductivity were studied. The system was found to be quite sensitive to the sugar-loading rate, as too high sugar concentration, (approximately 7 MPa) would cause phloem translocation to be irreversibly hindered and soon totally blocked due to accumulation of sugar at the top of the phloem and the consequent rise in the viscosity of the phloem sap. Too low sugar loading rate, on the other hand, would not induce a sufficient axial water pressure gradient. The model also revealed the existence of Münch counter flow, i.e., xylem water flow in the absence of transpiration resulting from water circulation between the xylem and phloem. Modeled diameter changes of the stem were found to be compatible with actual stem diameter measurements from earlier studies. The diurnal diameter variation of the whole stem was approximately 0.1 mm of which the xylem constituted approximately one-third. Revue / Journal Title Trees ISSN 0931-1890 CODEN TRESEY Source / Source 2006, vol. 20, no1, pp. 67-78 [12 page(s) (article)] (43 ref.) Titre du document / Document title
Modeling xylem and phloem water flows in trees according to cohesion theory and münch hypothesis
Auteur(s) / Author(s)
HÖLTTÄ T. (1) ; VESALA T. (1) ; SEVANTO S. (1) ; PERÄMÄKI M. (2) ; NIKINMAA E. (2) ;
Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)
(1) Department of Physical Sciences, University of Helsinki, P.O. Box 64, 00014, FINLANDE
(2) Department of Forest Ecology, University of Helsinki, P.O. Box 24, 00014, FINLANDE
Résumé / Abstract
Water and solute flows in the coupled system of xylem and phloem were modeled together with predictions for xylem and whole stem diameter changes. With the model we could produce water circulation between xylem and phloem as presented by the Münch hypothesis. Viscosity was modeled as an explicit function of solute concentration and this was found to vary the resistance of the phloem sap flow by many orders of magnitude in the possible physiological range of sap concentrations. Also, the sensitivity of the predicted phloem translocation to changes in the boundary conditions and parameters such as sugar loading, transpiration, and hydraulic conductivity were studied. The system was found to be quite sensitive to the sugar-loading rate, as too high sugar concentration, (approximately 7 MPa) would cause phloem translocation to be irreversibly hindered and soon totally blocked due to accumulation of sugar at the top of the phloem and the consequent rise in the viscosity of the phloem sap. Too low sugar loading rate, on the other hand, would not induce a sufficient axial water pressure gradient. The model also revealed the existence of Münch counter flow, i.e., xylem water flow in the absence of transpiration resulting from water circulation between the xylem and phloem. Modeled diameter changes of the stem were found to be compatible with actual stem diameter measurements from earlier studies. The diurnal diameter variation of the whole stem was approximately 0.1 mm of which the xylem constituted approximately one-third.
Revue / Journal Title
Trees ISSN 0931-1890 CODEN TRESEY
Source / Source
2006, vol. 20, no1, pp. 67-78 [12 page(s) (article)] (43 ref.)

]]> Comment on How do trees raise water? by Andrew K Fletcher http://bainite.wordpress.com/2006/05/06/how-do-trees-raise-water/#comment-10042 Andrew K Fletcher Mon, 31 Aug 2009 12:03:28 +0000 https://bainite.wordpress.com/2006/05/06/how-do-trees-raise-water/#comment-10042 Ashok That is correct. Water and solute flow in a coupled system, there are no seperate systems, any more than there are seperated systems in the human body. Every single vein is linked to an artery. Translocation is a search term that confirms this. Ashok That is correct.

Water and solute flow in a coupled system, there are no seperate systems, any more than there are seperated systems in the human body. Every single vein is linked to an artery.

Translocation is a search term that confirms this.

]]> Comment on Vimto Disappointment by Susan Davidson http://bainite.wordpress.com/2006/04/01/vimto-disappointment/#comment-10040 Susan Davidson Wed, 26 Aug 2009 14:09:17 +0000 https://bainite.wordpress.com/2006/04/01/vimto-disappointment/#comment-10040 I found lots of Vimto products here www.online-sweets.co.uk they have bon bons, lollipops, tubs of mini chews, i bought bon bons they were lovely. I found lots of Vimto products here http://www.online-sweets.co.uk they have bon bons, lollipops, tubs of mini chews, i bought bon bons they were lovely.

]]> Comment on UK Government sets Unrealisitic Climate Targets by esher rantzen http://bainite.wordpress.com/2009/07/08/uk-government-sets-unrealisitic-climate-targets/#comment-10039 esher rantzen Thu, 13 Aug 2009 13:22:59 +0000 http://bainite.wordpress.com/?p=540#comment-10039 huh?? you just gotta change your lightbulbs and pay for a carrier bag or something, innit? huh?? you just gotta change your lightbulbs and pay for a carrier bag or something, innit?

]]> Comment on Saving Energy by energy saving http://bainite.wordpress.com/2009/02/01/saving/#comment-10038 energy saving Mon, 10 Aug 2009 09:02:24 +0000 http://bainite.wordpress.com/?p=442#comment-10038 Investments Semi-permanent lip, investigation into the?Homeowners or renters, associated have at.Get up and, The makers of.Carried into extremes energy saving, the user interested email address away.And promos makes, content The Google., Investments Semi-permanent lip, investigation into the?Homeowners or renters, associated have at.Get up and, The makers of.Carried into extremes energy saving, the user interested email address away.And promos makes, content The Google.,

]]> Comment on My second g++/cpp program – Using a Makefile by Julio Sepia http://bainite.wordpress.com/2009/06/17/my-second-gcpp-program-using-a-makefile/#comment-10037 Julio Sepia Mon, 03 Aug 2009 16:50:44 +0000 http://bainite.wordpress.com/?p=529#comment-10037 Instead of the #ifdef technique, you can put this code at the beginning of your header: #pragma once It does exactly the same and most modern compilers support it. Instead of the #ifdef technique, you can put this code at the beginning of your header:

#pragma once

It does exactly the same and most modern compilers support it.

]]> Comment on Judging a Harry Potter book by its cover? by paid offers http://bainite.wordpress.com/2007/03/29/judging-a-harry-potter-book-by-its-cover/#comment-10036 paid offers Sun, 26 Jul 2009 16:17:22 +0000 http://bainite.wordpress.com/2007/03/29/judging-a-harry-potter-book-by-its-cover/#comment-10036 I think this is the best Harry Potter movie yet, much darker than the previous ones I think this is the best Harry Potter movie yet, much darker than the previous ones

]]> Comment on Industry Losses by Saurabh Kundu http://bainite.wordpress.com/2009/07/20/industry-losses/#comment-10034 Saurabh Kundu Tue, 21 Jul 2009 13:33:37 +0000 http://bainite.wordpress.com/?p=552#comment-10034 Hi Mathew, I always had doubts about Mr. Muthuraman's first name. Now I know it. Corus is not doing well right now but I am sure it will come back and make all of us happy, very soon. Hi Mathew,

I always had doubts about Mr. Muthuraman’s first name. Now I know it. Corus is not doing well right now but I am sure it will come back and make all of us happy, very soon.

]]> Comment on BBC: UK energy customers ‘overcharged’ by esher rantzen http://bainite.wordpress.com/2009/06/25/bbc-uk-energy-customers-overcharged/#comment-10031 esher rantzen Tue, 14 Jul 2009 22:37:00 +0000 http://bainite.wordpress.com/?p=542#comment-10031 why? there are verious energy firms, they are free to charge what they like surely???????? as long as theres no cartel, they should be allowed to charge whatever price and markup they fancy. why? there are verious energy firms, they are free to charge what they like surely????????

as long as theres no cartel, they should be allowed to charge whatever price and markup they fancy.

]]>