ASME SA213/ASTM A213 T91  seamless  alloy steel tube iss used for boiler,superheater and heat-exchanger etc.

ASME SA213/ASTM A213 T91 is equivalent to UNS K90901,ASME SA335/ASTM A335 P91, it included TYPE 1 & TYPE2. It has high

oxidation resistance and resistance to high temperature steam corrosion, but also has good impact toughness and high and stable

long-lasting plasticity and heat strength properties. In the use of temperature below 620 ° C, its permissible stress is higher than the

austenitic stainless steel.

Pro-hydrogen environment with the prevention of hydrogen embrittlement, hydrogen corrosion, hydrogen stripping, sulphide

corrosion performance, while having a good low temper brittleness, widely used in chemical manufacturing, petrochemical and

thermal power plant equipment manufacturing, such as ammonia reactors, coal gasification furnaces, converter furnaces, and

hydrogenation reactors, etc.

ASME SA213/ASTM A213 T91(Type 1) chemical composition:

C:0.07-0.14,Mn:0.3-0.6,P:0.02(Max),S:0.01(Max),Si:0.2-0.5,Ni:0.4(Max),Cr:8.0-9.5,Mo:0.85-1.05,V:0.18-..25,Nb:0.06-0.1,

N:0.03-0.07,Al:0.02(Max),Ti:0.01(Max),Zr:0.01(Max)

ASME SA213/ASTM A213 T91(Type 2) chemical composition:

C:0.08-0.12,Mn:0.3-0.5,P:0.02(Max),S:0.005(Max),Si:0.2-0.4,Ni:0.2(Max),Cr:8.0-9.5,Mo:0.85-1.05,V:0.18-..25,B: 0.001(Max)

Nb:0.06-0.1,N:0.035-0.07,Al:0.02(Max),W:0.05(Max),Ti:0.01(Max),Zr:0.01(Max) and some others…

In a word, ASME SA213/A213 T91 Type 2 is more complicated than Type 1.

ASME SA213/ASTM A213 T91(Type 1 & Type 2 are same) mechanical property:

Tensile Strength: 585 Mpa(Min), Yield Strength:415 Mpa(Min), Elongation: 20%(Min), Hardness: 90 HRB(Max).

boiler tubes, alloy tubes

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