1.4435

X2CrNiMo18-14-3

316L Mod

S31603

The UREA 316L grade has been specially developed for urea plant applications. It is a 316L modified stainless steel with extra – low silicon content and substantial higher molybdenum contents. The low carbon content, combined with a well balanced chemistry (low silicon and nickel content close to 14%) makes the alloy fully austenitic, free of intermetallic phase precipitations. The ferrite level is kept under 0.5% in the solution annealing and water quenched conditions.

The UREA 316L grade is designed for the fabrication of lining interiors in urea units for improved corrosion resistance properties in urea – carbonate environments or complementary products (pipes, fittings…). The alloy is not designed for nitric acid application.

Mechanical Properties

Tensile strength:	500-700	N/mm²
Yield strength 0,2% :	200	≥ N/mm²
Elongation:	40/30	≥ %
Hardness HB30:	215	≤ HB

Chemical Composition

CARBON

C

0,020% max

SILICON

Si

0,40% max

MAGNESE

Mn

2% max

PHOSPHORUS

P

0,045% max

SULPHUR

S

0,015% max

CHROMIUM

Cr

17-19% min

MOLYBDENUM

Mo

2,2-3%

Nickel

Ni

12,5-15,0%

at 1120 – 1180°C (2048 – 2156°F) followed by water quenching.

Welding The UREA 316L grade can be welded with most of the welding processes: TIG, Plasma, MIG welding, as well as SMAW, SAW or FCAW processes. The alloy is sensitive to hot cracking phenomenon due to its fully austenitic microstructure. Weld should be performed in order to obtain extra – low ferrite contents, no carbide or nitrides precipitations, low silicon contents as well as no intermetallic phases precipitations. Higher manganese content products should be considered.

OTHER UREA grades

Tensile strength:	490-690	N/mm²
Yield strength 0,2% :	205	≥ N/mm²
Elongation:	35	≥ %
Hardness HB30:	–	≤ HB

1.4435 – X2CrNiMo18-14-3 – 316L – S31603