difference between CS, LTCS and KCS

[Manav Malhotra]

Dear All,

 

Can anyone tell where all CS, LTCS and KCS is used? Is KCS is only used for equipments?

 

Regards,

Manav

[Raj]

Hi,

LTCS - Low temperature CS, used for Low Temparture applications i.e
Impact Tested @ -46 Deg C

CS - CS, Used for design temp applications i.e Impact Tested @ -29 Deg
C.

KCS - Killed steel is completely deoxidized steel. It is used in
petrochemical industries, specially in sower conditions and presence
of wet H2S

*Steel is considered to be carbon steel when no minimum content is
specified or required for chromium, cobalt, columbium [niobium],
molybdenum, nickel, titanium, tungsten, vanadium or zirconium, or any
other element to be added to obtain a desired alloying effect; when
the specified minimum for copper does not exceed 0.40 per cent; or
when the maximum content specified for any of the following elements
does not exceed the percentages noted: manganese 1.65, silicon 0.60,
copper 0.60.

*Low-temperature carbon steels have been developed chiefly for use in
low-temperature equipment and especially for welded pressure vessels.
They are low- to medium-carbon (0.20 to 0.30%), high-manganese (0.70
to 1.60%), silicon (0.15 to 0.60%) steels, which have a fine-grain
structure with uniform carbide dispersion. They feature moderate
strength with toughness down to — 50°F (—46°C).
For grain refinement and to improve formability and weldability,
carbon steels may contain 0.01 to 0.04% columbium. Called columbium
steels, they are used for shafts, forgings, gears, machine parts, and
dies and gages. Up to 0.15% sulfur, or 0.045 phosphorus, makes them
free-machining, but reduces strength.

*LTCS is a Nickel based alloy steel plates especially used for low
temperature applications below - 150 deg F. Mainly used in cryogenic
construction of space ships, low temperature application in chemical
plant below -55 deg C.

Examples:

SA-203 Steel Plate Grades A, B, D, E and F Nickle Alloy Steel Plates.
For low temperatures (-150 deg F)

Low Temperature Carbon Steel Tubes ASTM A334 Gr.1

ASTM A333——Seamless and Welded Steel Pipe for Low-Temperature Service:
Mainly Grade：
Grade 1, Grade 3, Grade 4, Grade 6, Grade 7, Grade 8, Grade 9, Grade
10, Grade 11

*ASTM A420 For LTCS Fittings.

*A350-LF2 is a standard For Flanges.

**Steel that are generally killed include:

· Steels with carbon contents greater then 0.25%

· All forging grades of steel.

· Structural steels with carbon content between 0.15 to 0.25%.

· Some special steel in the lower carbon ranges.

Cheers!

Raj