Seeking Advice on Optimal Chemical Composition for Tooth Adaptor Casting in HEMM Buckets.

[AjSCCMelt]

Hello everyone,

I’m looking for guidance on the best chemical composition or material grade to use for casting tooth adaptors used in Heavy Earth Moving Machinery (HEMM) buckets. Our goal is to achieve optimal durability and toughness in harsh working conditions without breaking.

We are currently exploring various steel alloys and would appreciate insights or recommendations on specific grades, heat treatment processes, or any other considerations that might enhance the performance and longevity of these cast components.

Thank you in advance for your expertise!

 

[EdStainless]

What do you have now that doesn't work?
Do they break or wear out first?
There is a fairly short list of materials used.


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P.E. Metallurgy, consulting work welcomed

 

[AjSCCMelt]

We are currently using the following self developed low alloy steel chemical composition but it is not in any standards.
The main issue in our material is that it breaks and the hardness achieved is very less than expected (i.e. 200-250BHN), it is expected to be around 400 BHN as per the OEM standards.
I'm looking for guidance on the standards that are being used in manufacturing these casting components (specifically tooth adaptors of the HEMM buckets).

 

[DAVIDSTECKER]

Have you looked at ASTM A128; Hadfield manganese?
It the cast version of the AR plate used in the earth mover buckets, rock crushers.

 

[EdStainless]

David's two suggestions are the leading two materials used in this service.

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P.E. Metallurgy, consulting work welcomed

 

[DAVIDSTECKER]

We make ships anchors out of the A128 for the Navy for its non-magnetic properties.
Thats after we remove the scale which is very labour intensive or a VERY scary acid bath.

 

[EdStainless]

Just acid pickling David.
In the SS business we use warm Nitric+HF.

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P.E. Metallurgy, consulting work welcomed

 

[AjSCCMelt]

@DAVIDSTECKER @EdStainless
We were thinking for the same as per IS 276 which is similar to ASTM A128, but was confused for which grade is suitable to have maximum life, while not causing any cracks/breakage. Please suggest which grade as per ASTM A218 can be used for the above application.

IMPORTANT NOTE:
The bucket is for a 42 CUM shovel.

 

[Tmoose]

"400 BHN as per the OEM standards."

Are you an aftermarket parts supplier?

I'd find some detailed close up pictures of failed tooth adapters interesting.
And with some new parts to help better understand any deformation that may have happened in addition to breakage.

Any history available RE: hours in service, etc ?

localized Poor Geometry and surface quality can drastically shorten fatigue life.
As can castings with internal defects.

Do you have mechanical material test results? What is the % elongation ?

 

[DAVIDSTECKER]

@EdStainless, I'm looking for the document that stated the acid and concentration, the passivating company in Kansas was freaked out by how aggressive it was.
We were etching the black scale off so they would be non-magnetic.

 

[DAVIDSTECKER]

@EdStainless, I found the Mil spec.
Some of it didn't copy right, but I think you'll get the jest of it.
MIL-S-17249
I love the part about the Government not having any responsibility if you use this for non-government work.

6.3 piC!diM. - A 1:1 hydrochloric acid solution at afiroximately 165”F. has
been found very effective. Conventional pickling such as 15 minutes in inhiMted
8 percent hydrofluortc acid in the temperature range of 150”’- 180°F. is also
recommended. Sulfuric acid pickling tends tc leave a smut on the work which
must be fluxed off prior to galvsnising.
~“”
‘Notice -When Government drawings, specification@, or other data are used
for~~pose other than in connection with a definitely related Government
i“ procurement operation, tbe United States Government thereby incurs no responsibility
nor any obligation whatsoever; and the fact that the Government may have
formulated, furnished, or in any way supplied the said drawings, specifications,
or otiier data, is not to be regarded by implication or otherwise as in any manner
licensing the holder or any other person or corporation, or conveying any rights
or perinission to manufacture, use, or sell any patented invention that may in
any way be related thereto.

 

[EdStainless]

Dave, ASTM A380 lists a bunch of pickle options.
In the SS business we used 40% nitric + 5% HF at about 140F.
We also used Sufuric + HF for some alloys.

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P.E. Metallurgy, consulting work welcomed

 

[DAVIDSTECKER]

EdStainless, we're making non-magnetic anchors for the Navy out of A128, so we use their drawings and specs.
We do make some parts from CF8M that we send out for pickling/passivating per ASTM A967 Nitric 5.
It does reference A380.
The castings are for the guiding the ropes on Ocean going tugboats.

 

[ShataCastings]

I agree with David that use ASTM A128 Hadfield manganese, almost all of the similar parts cast in my foundry are made of this material.

Mold design, casting temperature and pouring speed are also very important factors, to reduce porosity and shrinkages to make it stronger.

Bella Liu
Markting Manager
Hebei Shata Casthings Co., Ltd.
Shi Jiazhuang, Hebei Province, China

http://www.shatacastings.com

 

[jessieleo99]

I agree that ASTM A128 Hadfield manganese is an excellent choice due to its suitability for impact and abrasive conditions. However, it is also advisable to consider using austenitic manganese-nickel steel and chromium-molybdenum alloy steel (AISI 4140/4340) for such applications.

https://powder.samaterials.com/