Recent content by Yallapragada1022

For tool steels, you may want purchase this one: "Heat treatment, Selection and application of Tool Steels" by Bill Bryson (Hanser Gardner Publications). Hope this helps. Rao Yallapragada

ASM Heat Treater's guide recommends using a minimum annealing temperature of 1905 deg.F. The range is 1850 to 2050 deg.F. Again, just like EdStanless asked above, What are you trying to accomplish? Rao Yallapragada

Rockwell Tester - ASTM E-18. Microhardness - ASTM E384. Brinell Tester - ASTM E10. Mounting & Polishing - Use equipment supplier's recommended procedures or you can write your own procedures based on your in-house practices. Saw - you can write your own procedure based on your in-house...

You can contact Precision Steel Warehouse at (847) 455 7000. http://www.precisionsteel.com/ Hope this helps. Rao Yallapragada

E-6150: Equivalent grades: MIL-S-8503 AMS-6448, AMS-2301 http://www.suppliersonline.com/propertypages/6150.asp#chemistry This webpage has the chemistry information. I am not sure if there is an air craft grade 6150 out there. Hope this helps. Rao Yallapragada

As per ASM Heat Treater's Guide, 2nd edition, page 184: A quenched hardness of at least 55 HRC can be achieved if properly austenitized and quenched. The quenchants can be water / oil /polymer. You will have martensitic structure after quenching. The structure will not be martensitic if you...

EdStainless: Thanks for keeping the discussion going. I don't normally get a transition zone on a 4150H (quenched & tempered to 42 to 45.0 HRC) shaft that we induction harden because of very good quench. Case depth on this shaft is 0.250" to 0.350" to 50HRC. I do see a transition zone on a...

It makes sense to me know after I have read your 2nd post. Thanks Swall. Rao Yallapragada

Can you perform a complete metallurgical analysis in-house? You need to send the sample outside to have complete metallurgical analysis done, if you don't have a metallurgical lab in-house. It sounds like you only have some hardness data and you need to have a complete metallurgical...

Try to provide us with a picture of the zone you have been talking about. Rao Yallapragada

What is the quench temperature that you try to maintain? Rao Yallapragada

You may have to contact Carpenter Technologies to obtain the information. The company has some mechanical properties data on the website: http://www.cartech.com/common/frames.html?/techinfo/prodsearch.html&leftn=sao_products&lefto=nav_tlo&lefti=nav_tlo2 http://www.cartech.com/index.html Hope...

I agree with swall on proper way to figure out the soak time. We employ this method in our vacuum furnaces (carburizing) and other atmosphere furnaces (Carburizing & hardening). I also think that you won't go wrong with "One hour per inch" rule. Rao Yallapragada

You can apply "one hour per inch" soak after the furnace reaches the temperature. I am not sure why you are holding for 2:00 hours after furnace reaches the temperature. Hope this helps. Rao Yallapragada

Very interesting problem. I had to go through the same issue (splines & hole cracking) last year on 4150H shafts and we were able to address the issue by: 1) Lowering the heat input 2) Reducing the quench severity (Houghton Aqua Quench 365) - Lowered the quenchant GPM and increasing the...