LTCS vs. CS

[Chumpes]

Hi mechanician friends
I work on "corrosion" but I also have to deal with the compatibility of materials vs. low temperatures.

Is there a clear definition for Low Temperature Carbon Steel LTCS ?
If not, what do you understand when you see LTCS mentionned ?

Thanks

 

[SnTMan]

Chumpes, no clear definition that I know of, at least within Sec VIII, Div. 1. To me, LTCS just means "carbon steel that is suitable for the specified MDMT".

Regards,

Mike



The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[DSB123]

The Carbon steel must exhibit sufficient Toughness for the temperature at which it is operating

 

[DVWE]

Are you asking about any material form specifically?

In the piping world, LTCS usually refers to material from the A 333 specification.

I don't know that there is a clear definition of LTCS in the ASME realm, but if you look at the A 333 spec, it will guide you to which grades are impact tested at different low temps.

 

[Chumpes]

thank you all for these FAST answers ! (this was a general question, not linked to a particular grade)

Be carefull saying LTCS is "carbon steel that is suitable for the specified MDMT", one can understand that CS is "carbon steel that is NOT suitable for the specified MDMT" !! =)

I 've also already seen ITCS for Impact Tested Carbon Steel, that is probably a bit better than LTCS but still unsufficient, because testing temperature can be anything...

I agree with you, for me there is no clear definition of LTCS : we use the LTCS term just to show that MDMT is "quite low" and that material compatibility with MDMT shall be carefully checked. The use of selected CS grade/heat treatment delivery conditions/thickness/... to be covered by application of selected construction code.

I will try to change our habbits of specifying LTCS that does not mean much to me, and find another way to say what we meant.

thx again

 

[weldstan]

The Codes generally define the requirements for impact testing of CS below a specified temperature. For the most part. -20F was considered an appropriate temperature at which impact testing was not required. LTCS was generally used for exposure temps below -20F.

One caveat to the above is that most of the manufactured carbon steels listed for use at -20F and above could not meet "specified" absorbed energy values if/when impact tested at -20F.

 

[Dhurjati Sen]

Hi Chumpes,

I understand the following when LTCS is mentioned. The steel is inclusion free, as much as possible, it gives better mechanical properties including impact strength. Inclusion is controlled by Sulphur and Phosphorus content in steel and adding appropriate fluxes / deslagging methods as in secondary steel-making.

DHURJATI SEN