RE: 120] Fw: [MW:118] Forging Material SA-105 Vs SA-350 LF2
Agrawal Sunil (Mumbai -Stequ)
Thanks for info but the difference in chemical composition for above subject material is not substantial (see below):
SA 105: Carbon 0.35 max, Manganese 0.60 – 1.05
SA 350 LF2: Carbon 0.30, Manganese 0.60 – 1.35
Can you pl. throw some more light on how the above difference in chemical composition works (which allow us to use the SA 350 LF2 for lower temp as compare to SA 105)?
Further, is there any restricted manufacturing process for SA 350 that leads to finer grane, defect less structure, etc.?
Best Regards,
Sunil Agrawal
EDTICB-Mumbai (STEQU)
Ph.: +91 22 6777
7237
From: material...@googlegroups.com
[mailto:material...@googlegroups.com] On
Behalf Of Kannan....@Linde-LE.com
Sent: Monday, August 27, 2007 3:57
PM
To:
material...@googlegroups.com
Subject: [MW:120] Fw: [MW:118]
Forging Material SA-105 Vs SA-350 LF2
To add to the below...it is not mandatory to follow the
code as it is a guide. It is permitted to use even high temp. steels at low
temp. service with feasable additional restrictions called for.
For
instance, in this case A105 spec. does not call for charpy test. But if your
purc.spec is designed to call for the additional requirements, you can call for
it, if you are benifited by the change in overall.
With
regards,
Kannan.
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----- Forwarded by Kannan Sundaram/Internal/Baroda/LPTI/Linde-VA
on 27/08/2007 12:26 -----
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Kannan Sundaram/Internal/Baroda/LPTI/Linde-VA 27/08/2007 12:21 |
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The subject is the ability to withstand the sustained
stresses by the ductility and the grade of brittleness of the material from
ambient
to lower temp. evaluated by the charpy test. There is no crystal change
happening at lower temp. till -50.
The
below points may clarify your question.
1)
The composition difference is in the Carbon and Manganese composition inverse
variation.
2)
This effect makes the A350 better off than the A105 at lower temp. though the
phys. property is same at lower temp.
3)
The default heat treatment difference also helps A350 at lower temp. A350
requires min. Norm. or N&T or Q&T.
4)
Not the least the class of LF2 is generally not specified. But it is makes an
important diff. in the impact test requirement.
4)
The ASME recommends the min. temp. as -50 for A350 LF2. A105 till -20.
Finally
if the CE is same and Heat treatment is same and the Hardness being nearly
equal and if it passes the charpy test
definitely
A105 can be used below -20. However the welding may make the difference in why
not using the A105 below -20 as
Manganese
& Silicon makes an important difference in to use / not to use A105 at
temp. lower than -20. But the latest manufacturing
processes
can ensure the A105 manganese content at min.1.0%.
With
regards,
Kannan.
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"Agrawal
Sunil \(Mumbai -Stequ\)" <S.Ag...@ticb.com> 27/08/2007 11:11
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Dear Friends,
May I
request you to guide me about the basic difference between two forging Material
SA-105 Vs SA-350 LF2. Is it possible to use SA-105 below -29° C?
Best Regards,
Sunil Agrawal
EDTICB-Mumbai (STEQU)
Ph.: +91 22 6777 7237
<br
Kannan....@linde-le.com
I have attached a metallographic original picture of a sample tested recently of one major European supplier for reference. However it is of a pipe material and not of forging. But it could be of good comparision. The extreme fine grain is clearly visible which was obtained by Q&T process of hot mill product and was statistically considered to be one of the best supplier for LT pipe & thier HT process. The charpy value was 145 against >=12J.
Also the yield strength changes considerably in coarse-grained than fine-grained steel during aging process. Also brittleness increases after the aging in coarse-grained steel. So the heat treatment is the key complimented by the managanese & silicon %. On the effect of manganese I will write in detail tomorrow.
With regards,
Kannan.
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| "Agrawal Sunil \(Mumbai
-Stequ\)" <S.Ag...@ticb.com>
Sent by: material...@googlegroups.com |
27/08/2007 13:37
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