WB36

WB36 is a bainitic Ni-Cu-Mo steel micro-alloyed with niobium according German standards DIN WB36 .

WB36 alloy steel boiler, superheater, and heat-exchanger pipe

It is also known as 15NiCuMoNb5-6-4 according to EN 10216-2,ASTM A213 T36 and ASTM A335 P36.

The range of WB36 pipe sizes that may be examined by each method shall be subjected to the limitations in the scope of the respective practice.

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Challenges

WB36 exhibits excellent high-strength properties up to 450 °C. The reduced weight of the feedwater piping components compared with conventional carbon steel allows improved resistance to thermal fatigue and very good heat transfer.

15NiCuMoNb5 pipe chemical composition and Mechanical property are shown as figure below:

15NiCuMoNb5 chemical composition (％)

Material	WB36
C	≤0.17
N	≤0.020
Cr	≤0.30
P	≤ 0.025
S	≤0.01
Mn	0.80~1.20
Mo	0.25~0.50
Ni	1.00~1.30
Cu	0.50~0.80
Si	0.25~0.50
Nb	0.015~0.045

Mechanical property

Yield strength( Mpa) at RT ———- 350℃	Ultimate tensile strength Mpa	Uniform elongation A₅ (%)
430         353	610-760	≥16

Application

This grade is mainly used in high-pressure, medium-temperature feedwater lines (close to 400 °C).