I got a peace of Suminagashi steel form here.
The description seems to me be heat treated in the same way as the O1. Is it right, or what else should be paying attention?
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I got a peace of Suminagashi steel form here.
The description seems to me be heat treated in the same way as the O1. Is it right, or what else should be paying attention?
I have a Brian Brown (http://straightrazorpalace.com/membe...emarker60.html) - Badger & Blade LE from this material and I believe that Bruno (http://straightrazorpalace.com/members/bruno.html) has also.
Hopefully one of them will chime in...
I hope so. :) Thanks!
It is indeed pretty much like O1. However, there are a few details you may want to mind. Firstly, you want to preheat the oil. Secondly, you will want no sharp indentations where the thermal shock could rip the sides apart. Otherwise one of the sides might peel away like a banana peel. Third you will want to do the tempering before you do anything else. Or the razor might still rip lengthwise.
Grinding it post HT can be a bit challenging because the hard edge material will behave very differently to the soft sides material.
You need to protect the edge while etching the material. Best etched with Ferric Chloride.
And if you are in the process of etching, and you notice that there are blotchy areas that won't etch black, it means that the HT has failed and those areas are not fully hardened.
Personally I don't like working it because the sides stay soft and you always need to hone with tape. And there is always the chance of small lengthwise cracks here or there.
What temperature do you offer?Quote:
Originally Posted by Bruno
Sorry, I dont understand. What do you mean here?Quote:
Originally Posted by Bruno
It is standard procedure, isn't it?Quote:
Originally Posted by Bruno
Thank you for all!
I take a big chunk of mild steel, bring it to red heat, dunk it in the oil and stir it around. I think it is about 50 degrees celcius.
With ripping apart, I mean that the mild steel sides will contract very different from the steel core. If there are notches or ridges somewhere, that could be enough stress to rip a side from the steel. I have had this 2 or 3 times.
In this pic you can see that I had file a notch in the front side of the point. that was enough stress for the mechanical shock to just peel away one side. The data sheet also says you can do either water quench or oil quench. I suggest not doing water quench on a razor. Because the sides will still be very thick, and the contractions in the water quench are so strong that it can rip apart your razor even if you have no notches or ridges.
Attachment 219513
I see. Thank you, Bruno!
And this my friends is why custom Razor with exotic materials are expensive as the Smith has to make up for potentially losses of time & materials from failures just like theseQuote:
Originally Posted by Bruno
Bruno, just a side question,
with simple carbon steels 1075 to 1095 steel I preheat my quenching oil (Canola) to 70°C as this is recommended for them & works for me with out trouble,
I would have thought the Suminagashi would have needed to have a warmer quench oil than 50° also to help avoid the potential losses like in your photo,
I know minor temperature changes can make a big difference when heat treating even a 50°C (6% of 800°) difference in the steel temp can effect it greatly?
as well as using a dunking v's swirling the blade motion in the oil during the initial quench movements,
this is only my thoughts as I have not used any San Mai or similar welded steels.
could this preheat temp difference also be due to the medium of Maize v's Canola oil?
sorry if this is rambling, I'm just thinking out loud with curiosity
After reading about martempering, it seems that the speed from 220 C down to 100 C is where you want to slow things down to reduce stress. The temp of the oil would have a huge effect on the rate of cooling at these steel temps.
That could very well be. In that case you could use a deep fryer to preheat the oil and quench in that.Quote:
Originally Posted by bluesman7
In any case, no matter how you quench, the difference between the mild steel sides and the 1.3% carbon steel core means that there is always going to be the risk of a violent split.
I agree. After I posted I was thinking that this is not really the same thing as quench cracking in a single alloy steel. It still makes sense to make the tail end of the quench as gentle as possible though.Quote:
Originally Posted by Bruno
I have done several razors now in Suminagashi and I heat up my medium speed quenching oil (same I use for 01) to 80c. No cracks, splits or anything. It has been flawless so far. This MO works great for me.
I tested quenching with A. a faster quenching oil (Parks 50) and B. with lower temps using both fast and medium oil (50C and 60C) and I got cracks towards the edge.
That settles it then. I probably quenched too cold. I'll have to buy a cheap fryer and mount it my quench tank
I will try with canola oil. Thanks!Quote:
Originally Posted by Maximilian
Bruno, that's what I do. I also use a separate digital cooking thermometer to double check the temp as the thermostat from those fryers are usually not very accurate.Quote:
Originally Posted by Bruno
I've been heating my oil in a double boiler set up and using a candy thermometer. The double boiler works well in that I can also easily cool the oil with a bath of cool water if I get it too warm.
When Quenching I use a dual read out Thermo couple
1 in my forge & 1 in my oil
Attachment 220408Attachment 220409
Nice setup, thank you for sharing!
Okay so I went to customer service and got response next day :<0)
Thank you very much for your inquiry.
The item comes with instruction:
Attachment 220494
Best regards
Customer Service
Update!
I maked a kamisori and everything was perfect. The grindig was difficult as Bruno said. I am pleased with the results. I got fine and sharp edge. Thank you for your help!
My process:
I leaved 1.5 mm thikness of the edge.
soaking: 805C / 1480F, 8 min.
quenching oil: 80C 20 sec - Thanks Maximilian
tempering: after cooling to room temperature, 210C 2x1h (between cooling to room temperature)
After this I sanded a few tenths of millimeters from the edge.
Attachment 221384
That looks pretty good. The etching came out very nice, and I like the pattern on the handle.
Thank you, Bruno! I am really happy with this steel. I got a very smooth edge.
Sorry I missed this post. Looks like you got some good advice and everything worked out great.
I've made around 75-80 razors out of that material and I would say 95-98% have been no problem at all.
Good looking Razor! Keep it up.
Thank you very much. I am glad to you like it.
"75-80 razors" - not bad. :)
Looking Great, can you get "Parks 50" quenching oil? I use it but it is harder to get every year.
The old deep fryer gets to pre-heat 130-170F. works great for a free fryer from the scrap yard.
Thanks! I used canola-oil. I preheated on my cooking plate in a NESQUIK chocolate powder box (made of steel). :)
Hello again!
Unfortunately I have problem with the heat treatment of suminagashi steel. I do not understand: sometimes work my process, sometimes not.
I do not get the smooth edge, just britle.
Can anyone use canola oil for quenching this steel? I think this is my problem. I am warm it up to 80C.
I tested quenching lukewarm water as well. But this is more risk, I know.
My hardening range: 780-810C, soaking time: 7-8mins, quenching time: 15-20sec, tempering range: 180-210C - 2x1h.
I cant measure the hardness I can rely on my experience so far.
Could someone recommend a good oil to use instead of canola? And I can get it from Europe...:)
Thank you for the private advices to Maxim and Mike!
I continue my tests....thanks in advance all the help!
Hi Gregg,
I using this one: Härteöl 5 Liter Kanister: Amazon.de: Baumarkt
But I dont think, the oil is the problem. Before this special hardening oil I used simple canola oil too and it also works. In my opinion the problem is the steel itself. Perhaps in the production process there will sometimes somthing wrong. Your hardening process looks ok for me. I would go a littel bit higher with the temperature (825 C) with a little bit less time (4-5 mins), but this could not be a great difference. Perhaps you overheat the steel a little bit before the hardening with grinding? Test a normalizing before the hardening. Go with the razor several times to approx. 725C and let it cool down moving it on the air. Perhaps its work.
Actuall I dont using the suminagashi anymore. The look is fine, but from the shaving performance for me there are better steels out there.
Hi,
thank you so much for the quick answer.
What speed has this oil what you use? Why did you change from canolia if it is worked for you?
"Perhaps you overheat the steel a little bit before the hardening with grinding? " - I think you are right. Nowadays I use a very speed grinding method with clamps. Sometimes the steel is colorised to blue and brown. I did not make normalizing because I am not forging. It can cause my problems, I think and I hope. :)
"Actuall I dont using the suminagashi anymore. The look is fine, but from the shaving performance for me there are better steels out there."
I agree, but the people like it. :)
How much time soaking: 4-5 mins?Quote:
Originally Posted by Buddel
Cooling down on the aire to room temperature or how many?
Thanks!
To be honest, I dont know it. I changed, because my workshop smelled always like a french fries restaurant, after the hardening and heat treatment. I using an old friteuse for the process. I hoped the new oil will reduce this. It will... now it smells more like a overheat motor :DQuote:
Originally Posted by gregg71
How much time soaking: 4-5 mins? --> yes
Cooling down on the aire to room temperature or how many? --> I dont know exactlly. I wait approx. 1 min. before I will put it back in the oven. This is pendular tempering to remove stress from the steel and make a finer grain.
Thank you so much for your response! You have given me a new hope. :)
I would go a little higher with the steel temperature. 825. And a shorter soak.
Your oil is just fine. The cheapest corn oil will do.
Also, how quickly do you get from the oven to the quench? This is shallow hardening steel so any drop in temperature below critical will greatly affect performance.
[QUOTE=gregg71;1628406] Sometimes the steel is colorised to blue and brown. I did not make normalizing because I am not forging. [QUOTE]
I personally think this may be your cause right here
I haven't used any laminated (welded) steels yet, but my understanding is you need to always stress relieve/normalize after grinding whether forged or stock removal, for this very reason as the grinding process creates stresses in mono steel let alone the laminated steels
Thanks, Bruno, I will try!
In one second.Quote:
Originally Posted by Bruno
Thanks, but I made around 15 razors without any problem. The only differnce is maybe I use a very speed grinding method with clamps nowadays. I dont know.Quote:
Originally Posted by gregg71
