Where the
world gathers for metal finishing
Q&As since 1989


-----

Replacements for 4750 Steel

 

What are the components of Hastelloy, Ni, Fe, Cr, etc? Anybody have a less expensive substitute for 4750 steel? Laser application? 1/2" dia. rod, small turned part.

Bill vail
- Boulder, Colorado, USA

---

Question 1. Which Hastelloy? They're all Ni-base alloys but there are dozens of grades with significantly different details. Usually identified with a letter or alphanumeric suffix, for instance "Hastelloy B" or Hastelloy C-276".

Question 2. 4750 would be a simple Ni-Cr-Mo low alloy steel. What mechanical properties do you want (strength, hardness etc)? Those requirements plus the section thickness (which you have already given as 1/2 inch) will lead to a list of suitable steels and you could then price supply of each grade.

Bill Reynolds [deceased]
consultant metallurgist - Ballarat, Victoria, Australia
We sadly relate the news that Bill passed away on Jan. 29, 2010.
 

---

Hello Bill!

Hastelloy information can be found at www.haynesintl.com/CRAfab/CRAfabH2010E.htm, a page from Haynes International's site.

I don't know what you mean by "4750" steel. WE use that as essentially a slang term for nickel iron magnetic metal, with 47-50% nickel in it, because that's what Allegheny Ludlum called it back when they made it. There is no 4750 in the AISI system, nor is it a former standard SAE steel. Can you clarify?

Good luck!

Lee Gearhart
metallurgist - E. Aurora, New York
 

---

Hello Lee,

Re 4750. The AISI system for carbon and low alloy steels uses the first two digits to specify standardised alloy levels (47 = nominal 1%Ni 0.5%Cr 0.25%Mo) and the last two digits to specify the nominal carbon level with the decimal point omitted (50 = 0.50%C). While there are many "standard" or established AISI grades, the system is available to describe other grades (such as 4750). I didn't consider the possibility that someone would come up with a house designation that complied with an established naming protocol but had a substantially different meaning. Live and learn!

Bill Reynolds [deceased]
consultant metallurgist - Ballarat, Victoria, Australia
We sadly relate the news that Bill passed away on Jan. 29, 2010.