[TheForge] Harden & temper

Thu Jun 16 11:10:32 EDT 2011

Super Quench is nothing but a fast quench -- equal to a NaOH solution quench 
in speed.  It is just safer than using caustic.  Use of caustic has been 
around in industry for years and is really not too much faster than a brine 
quench.  In industrial use high velocity water sprays can do a similar 
quench because they also break up / prevent a steam film or layer happening 
during the quench.

Dave Smucker

--------------------------------------------------
From: "Bruce Freeman" <freemab222 at gmail.com>
Sent: Thursday, June 16, 2011 9:09 AM
To: "Blacksmithing List Sponsored by ABANA" <theforge at mailman.qth.net>
Subject: Re: [TheForge] Harden & temper

> Anyone know how this compares to SuperQuench?  I get the impression
> they're quite different, but the comparison is obvious.
>
> On Wed, Jun 15, 2011 at 1:51 PM, peter fels <artgawk at thegrid.net> wrote:
>> Neat...looking forward to how it shakes out by the time it gets down to 
>> us.
>>
>> On Jun 15, 2011, at 8:20 AM, williamsiron at comcast.net wrote:
>>
>>>
>>>
>>> For all you blacksmiths that harden & temper steel. I came across this 
>>> article and thought you might be interested. The fellow discovered a way 
>>> to harden/temper steel in about 10 seconds.
>>>
>>> +++++++++++++++++++++++++++++++++++++++++++
>>>
>>> Development of rapid heating and cooling (flash processing) process to 
>>> produce advanced high strength steel microstructures
>>>
>>>
>>>
>>> Authors: Lolla, T; Cola, G; Narayanan, B; Alexandrov, B; Babu, S S
>>>
>>>
>>>
>>> Source: Materials Science and Technology , Volume 27, Number 5, May 2011 
>>> , pp. 863-875
>>>
>>>
>>>
>>>
>>> Top of Form
>>>
>>>
>>>
>>>
>>> Bottom of Form
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> Abstract:
>>>
>>>
>>>
>>>
>>>
>>> Flash processing of an AISI8620 steel sheet, which involves rapid 
>>> heating and cooling with an overall process duration of <10 s, produced 
>>> a steel microstructure with a high tensile strength and good ductility 
>>> similar to that of advanced high strength steels. Flash processed steel 
>>> [ultimate tensile strength (UTS): 1694 MPa, elongation: 7·1%], showed at 
>>> least 7% higher UTS and 30% greater elongation than published results on 
>>> martensitic advanced high strength steel (UTS: 1585 MPa, elongation: 
>>> 5·1%). The underlying microstructure was characterised with optical, 
>>> scanning electron, transmission electron microscopy as well as hardness 
>>> mapping. A complex distribution of bainitic and martensite 
>>> microstructures with carbides was observed. A mechanism for the above 
>>> microstructure evolution is proposed.
>>>
>>>
>>>
>>> Articles that cite this article?
>>>
>>>
>>>
>>> Keywords: Flash processing ; Phase transformation ; Bainite ; 
>>> Microstructure characterisation ; Advanced high strength steels ; Heat 
>>> treatment
>>>
>>>
>>>
>>> Document Type: Original Article
>>>
>>>
>>>
>>> DOI: 10.1179/174328409X433813
>>>
>>>
>>>
>>> A Detroit entrepreneur surprised engineers at Ohio State University 
>>> recently when he invented a heat-treatment that makes steel 7 percent 
>>> stronger than any steel on record – in less than 10 seconds.
>>>
>>> In fact, the steel, now trademarked as Flash Bainite , has tested 
>>> stronger and more shock-absorbing than the most common titanium alloys 
>>> used by industry.
>>>
>>> Now the entrepreneur is working with researchers at Ohio State 
>>> University to better understand the science behind the new treatment, 
>>> called flash processing.
>>>
>>> What they’ve discovered may hold the key to making cars and military 
>>> vehicles lighter, stronger, and more fuel-efficient.
>>>
>>> In the current issue of the journal Materials Science and Technology , 
>>> the inventor and his Ohio State partners describe how rapidly heating 
>>> and cooling steel sheets changes the microstructure inside the alloy to 
>>> make it stronger and less brittle.
>>>
>>> The basic process of heat-treating steel has changed little in the 
>>> modern age, and engineer Suresh Babu is one of few researchers worldwide 
>>> who still study how to tune the properties of steel in detail. He’s an 
>>> associate professor of materials science and engineering at Ohio State, 
>>> and Director of the National Science Foundation (NSF) Center for 
>>> Integrative Materials Joining for Energy Applications, headquartered at 
>>> the university.
>>>
>>> “Steel is what we would call a ‘mature technology.’ We’d like to think 
>>> we know most everything about it,” he said. “If someone invented a way 
>>> to strengthen the strongest steels even a few percent, that would be a 
>>> big deal. But 7 percent? That’s huge.”
>>>
>>> Yet, when inventor Gary Cola initially approached him, Babu didn’t know 
>>> what to think.
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> “The process that Gary described – it shouldn’t have worked,” he said. 
>>> “I didn’t believe him. So he took my students and me to Detroit.”
>>>
>>> Cola showed them his proprietary lab setup at SFP Works, LLC., where 
>>> rollers carried steel sheets through flames as hot as 1100 degrees 
>>> Celsius and then into a cooling liquid bath.
>>>
>>>
>>>
>>> Though the typical temperature and length of time for hardening varies 
>>> by industry, most steels are heat-treated at around 900 degrees Celsius 
>>> for a few hours. Others are heated at similar temperatures for days.
>>>
>>> Cola’s entire process took less than 10 seconds.
>>>
>>> He claimed that the resulting steel was 7 percent stronger than 
>>> martensitic advanced high-strength steel. [Martensitic steel is so named 
>>> because the internal microstructure is entirely composed of a crystal 
>>> form called martensite.] Cola further claimed that his steel could be 
>>> drawn – that is, thinned and lengthened – 30 percent more than 
>>> martensitic steels without losing its enhanced strength.
>>>
>>> If that were true, then Cola’s steel could enable carmakers to build 
>>> frames that are up to 30 percent thinner and lighter without 
>>> compromising safety. Or, it could reinforce an armored vehicle without 
>>> weighing it down.
>>>
>>> “We asked for a few samples to test, and it turned out that everything 
>>> he said was true,” said Ohio State graduate student Tapasvi Lolla. “Then 
>>> it was up to us to understand what was happening.”
>>>
>>> Cola is a self-taught metallurgist, and he wanted help from Babu and his 
>>> team to reveal the physics behind the process – to understand it in 
>>> detail so that he could find ways to adapt it and even improve it.
>>>
>>> He partnered with Ohio State to provide research support for Brian 
>>> Hanhold, who was an undergraduate student at the time, and Lolla, who 
>>> subsequently earned his master’s degree working out the answer.
>>>
>>> Using an electron microscope, they discovered that Cola’s process did 
>>> indeed form martensite microstructure inside the steel. But they also 
>>> saw another form called bainite microstructure, scattered with 
>>> carbon-rich compounds called carbides.
>>>
>>> In traditional, slow heat treatments, steel’s initial microstructure 
>>> always dissolves into a homogeneous phase called austenite at peak 
>>> temperature, Babu explained. But as the steel cools rapidly from this 
>>> high temperature, all of the austenite normally transforms into 
>>> martensite.
>>>
>>>
>>>
>>> “We think that, because this new process is so fast with rapid heating 
>>> and cooling, the carbides don’t get a chance to dissolve completely 
>>> within austenite at high temperature, so they remain in the steel and 
>>> make this unique microstructure containing bainite, martensite and 
>>> carbides,” Babu said.
>>>
>>> Lolla pointed out that this unique microstructure boosts ductility --  
>>> meaning that the steel can crumple a great deal before breaking – making 
>>> it a potential impact-absorber for automotive applications.
>>>
>>> Babu, Lolla, Ohio State research scientist Boian Alexandrov, and Cola 
>>> co-authored the paper with Badri Narayanan, a doctoral student in 
>>> materials science and engineering.
>>>
>>> Now Hanhold is working to carry over his lessons into welding 
>>> engineering, where he hopes to solve the problem of heat-induced 
>>> weakening during welding. High-strength steel often weakens just outside 
>>> the weld joint, where the alloy has been heated and cooled. Hanhold 
>>> suspects that bringing the speed of Cola’s method to welding might 
>>> minimize the damage to adjacent areas and reduce the weakening.
>>>
>>> If he succeeds, his discovery will benefit industrial partners of the 
>>> NSF Center for Integrative Materials Joining Science for Energy 
>>> Applications, which formed earlier this year. Ohio State’s academic 
>>> partners on the center include Lehigh University, the University of 
>>> Wisconsin-Madison, and the Colorado School of Mines.
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> ______________________________________________________________
>>> TheForge mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/theforge
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:TheForge at mailman.qth.net
>>>
>>> TheForge mail list group photo site is
>>> http://www.photoworks.com
>>> Login: blacksmithblacksmith at hotmail.com
>>> Password: anvil
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>
>> ______________________________________________________________
>> TheForge mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/theforge
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:TheForge at mailman.qth.net
>>
>> TheForge mail list group photo site is
>> http://www.photoworks.com
>> Login: blacksmithblacksmith at hotmail.com
>> Password: anvil
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>
>
>
> -- 
> Bruce
> NJ
> ______________________________________________________________
> TheForge mailing list
> Home: http://mailman.qth.net/mailman/listinfo/theforge
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:TheForge at mailman.qth.net
>
> TheForge mail list group photo site is
> http://www.photoworks.com
> Login: blacksmithblacksmith at hotmail.com
> Password: anvil
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html 