1090 Steel question 2

[Jsthompson]

I think i have 1090 steel, the 850 degree C water quench gave an HRC hardness of around 63. What i am looking for is how to obtain a Charpy value of 20 J. I need a heat treatment process or a relative hardness to obtain this.

 

[metengr]

A Charpy impact value of 20 J at ambient temperature?

 

[Carburize]

Is this just an experiment or are you trying to make a component?
If it's an experiment a long temper at 650 C to reduce the hardness to around 22Rc might get you there, if it's for a component change the material!

 

[Jsthompson]

It is for an expirament. I have to use 1090. Im guessing that by your reaction I could heat it to a certain temperature and perform the charpy test to obtain a impact energy of 20J. what temperature should i heat to?

 

[metengr]

I reviewed a graph of impact energy versus carbon content. I don't believe you can hit 20 J at room temperature even with a quench and temper for a crbon content of 0.90%.

You can try to temper the quenched specimen at 1250 deg F for 1 hour and run a Charpy impact test. With this carbon content, you would be lucky to reach 7J at ambient temperature.

 

[Salvatio]

try to apply several stages of quenching upon austenizing, perhaps around 1000 degC. To obtain high hardness, you'll need larger austenite grain, such that nucleation could be minimized. Perhaps with a dual-phase or even a three-phase structure upon such stages of quench would increase the impact strength. You might want to use water quench as the last quenching medium.

You can have a start off with oil-air-brine solution/water...However, do keep in mind that you will need to keep in mind that time taken for each quench varies, and to find the perfect time, is through trial and error.

Good luck.