17-4 stainless terminology

R

RJT

Titanium

Joined

Aug 24, 2006

Location

greensboro,northcarolina

• Jan 26, 2012

• #1

17-4 can be heat reated to 45 -47 R/C from what I am reading. You can buy it annealed with a brinell hardness of 353 (about 38 R/C) from McMaster Carr, but is is still called 17-4 PH? Is it usually offered annealed or heat treated? We use a lot of 420 and 440 and always buy it annealed, machine it and vacuum heat treat it. We buy 4140 either PHT or annealed and then heat treat it. But 17-4 is usually labeled 17-4 PH even if it is annealed. What's the story?

 

johnoder

Diamond

Joined

Jul 16, 2004

Location

Houston, TX USA

• Jan 26, 2012

• #2

The ONLY 17PH4 heat treated is ALWAYS followed by one of several "H" designations

H1150
H1100 , HH1100 (Double)
H1025
H900 (about mid forties RC)

Annealed is "A", a definitely not 38 RC

 

redlee

Titanium

Joined

Apr 2, 2009

Location

Beaver County Alb. Canada

• Jan 26, 2012

• #3

PH Stands for Percipitation Hardenable.

 

T

trevj

Titanium

Joined

May 17, 2005

Location

Interior British Columbia

• Jan 26, 2012

• #4

Yeah. The stuff is 17-4PH, no matter what state it is in. Precipitation Hardening = PH.

Gotta watch the H-number at the end, or the hardness.

Best is if you have the capability to test the hardness yourself.

Precipitation Hardening steels are pretty easy to heat treat. Read the recipe, set the temperature, cook for the correct length of time for the thickness, and allow it to cool.

Cheers
Trev

 

S

sean9c

Hot Rolled

Joined

Oct 5, 2009

Location

Anacortes, WA USA

• Jan 26, 2012

• #5

17-4 refers to the chromium/nickel content of the material that doesn't change with HT.

 

JRIowa

Diamond

Joined

May 27, 2003

Location

Marshalltown, Iowa, USA

• Jan 26, 2012

• #6

johnoder said:

The ONLY 17PH4 heat treated is ALWAYS followed by one of several "H" designations

H1150
H1100 , HH1100 (Double)
H1025
H900 (about mid forties RC)

Annealed is "A", a definitely not 38 RC

Click to expand...

John,
Don't you mean HH1150?
Also, H1075 (rare) and H1150M (really rare)
JR

 

johnoder

Diamond

Joined

Jul 16, 2004

Location

Houston, TX USA

• Jan 26, 2012

• #7

JR is correct and I am wrong on the HH1150

J.O.

 

Bobw

Diamond

Joined

Feb 8, 2005

Location

Hatch, NM Chile capital of the WORLD

• Jan 26, 2012

• #8

I'm pretty sure what we call "annealed" 17-4 is actually solution treated, as in the state ready to be precipitation hardened.

Dig through the specs or the EMJ material bible, there is a process to anneal and then bring it back to a solution treated state.

Already been said, the confusion is that PH is precipitation hardening.

Kind of like how the L in 304L is different than the L in 12L14.

 

M

metlmunchr

Diamond

Joined

Jul 25, 2004

Location

Asheville NC USA

• Jan 26, 2012

• #9

This article Precipitation Hardening Stainless Steels - Alloys, Properties, Fabrication Processes, Supplier Data will tell you quite a bit about 17-4 stainless.

As mentioned above, its important to understand that the "PH" designation does not mean pre-hardened, but rather means precipitation hardenable. Its also my understanding that the terms "annealled" and "solution heat treated" are used interchangably when referring to precipitation hardening stainless steels.

 

JRIowa

Diamond

Joined

May 27, 2003

Location

Marshalltown, Iowa, USA

• Jan 26, 2012

• #10

johnoder said:

JR is correct and I am wrong on the HH1150

J.O.

Click to expand...

This is pretty early in the year for your annual mistake
JR