Bad stainless steel, ever seen this?

S

SND

Diamond

Joined

Jan 12, 2003

Location

Canada

• Jun 30, 2010

• #1

Was at a customers shop yesterday and a couple of these landed in, just the roughing stage.
Material is 316SS, starts from 7 or 8" solid round bar, hole is about 6" and 10" deep of so.
I've seen this sort of look on aluminum a few times, and definitely had some horrible to machine stainless before, or cracks a few times, but never saw this with stainless until now.
They have certs and all, but I don't know yet who's the mill that made it and in what country.

Any thoughts on what causes this? looks like the batch wasn't mixed right. I wonder what it might do to the actual integrity of the material, perhaps more corrosion prone in that area, or weaker?

 

Kingbob

Stainless

Joined

Dec 1, 2009

Location

Louisiana

• Jun 30, 2010

• #2

never seen that one before in stainless, hmm is kaiser making stainless now? lol

 

V

vraptor

Cast Iron

Joined

May 30, 2006

Location

Friendswood, Texas

• Jun 30, 2010

• #3

Damn! That sure looks like what you see when you polish a meteorite.

 

I

IndGild

Hot Rolled

Joined

Mar 2, 2007

Location

ct

• Jun 30, 2010

• #4

I believe who ever was mixing it put little bit of concrete,
just to make it stronger , harder or whatever



looks nice

 

KIMFAB

Stainless

Joined

Jun 21, 2008

Location

Logandale,Nv

• Jun 30, 2010

• #5

Almost looks like the crystals you see in zinc.

 

IAMATT

Stainless

Joined

Aug 3, 2009

Location

LAS VEGAS, NV

• Jun 30, 2010

• #6

Kingbob said:

never seen that one before in stainless, hmm is kaiser making stainless now? lol

Click to expand...

Thank you for that...it was awesome!

 

AIR-O-LATOR

Aluminum

Joined

Aug 27, 2007

Location

Kansas City Missouri

• Jun 30, 2010

• #7

We use alot of 316 or 304 and I've seen pourous castings and sand in the casting but never on billet. However we used iron foundry and thats what some of the ductile casting would come in looking like after machining them. They didnt quite get the mix right when they poured. Harder than the knobs of hell they were to machine.

 

JRIowa

Diamond

Joined

May 27, 2003

Location

Marshalltown, Iowa, USA

• Jun 30, 2010

• #8

I showed this to our materials guru. Kinda what I thought, but he confirmed. The mill either didn't heat the ingot enough or it just wasn't worked enough to get the cast structure out.

China or Romania would be my bet.
JR

 

C

Canela

Aluminum

Joined

Feb 26, 2010

Location

Barcelona

• Jun 30, 2010

• #9

Never saw that before in a solid round bar but this is a problem that tipically appears in cast parts when the water quench is not made at the right temperature, this will affect to corrossion resistance

 

S

Stu Miller

Hot Rolled

Joined

Apr 8, 2002

Location

Covington, Wa

• Jun 30, 2010

• #10

It looks to me like different parts of the bar? casting? cooled at different rates. The normal small grain structure resulting from fairly rapid cooling, the large crystals resulting from slow cooling from high temperature, allowing the crystals to grow. I don't think it has anything to do with impurities

 

L

loggerhogger

Stainless

Joined

Aug 12, 2005

Location

Tacoma Washington

• Jun 30, 2010

• #11

I didn't know that you had to galvanize stainless.

 

Nutznbolts

Plastic

Joined

Jan 28, 2007

Location

Newcastle, NSW, Australia

• Jun 30, 2010

• #12

2c worth

I once saw a similar effect in some flat bar "316".
It was magnetic "316" in the different lookng areas.
I rejected the lot but it was never explained.

I have also seen the like in HAZ.