ASTM A249/A249M Type 347H Introduce

ASTM A249/A249M Type 347H is an austenitic stainless steel specifically designed for use in boiler, superheater and heat exchanger tubes, which contain higher amounts of chromium and nickel compared to other stainless steels. This grade of steel is popular for its ability to resist corrosion and oxidation, and for its high strength-to-weight ratio. Due to its outstanding properties, it is ideal for a range of applications, such as pressure vessels, heat exchangers, and condensers.

Smelting temperature:1659°C - 1768°C

Application:Welded austenitic steel tubes for boilers, superheaters, heat exchangers and condensers

ASTM A249/A249M Type 347H Material Chemical Composition

The chemical composition of the ASTM A249/A249M Type 347H steel are as follows:

ElementMinMax
Silicon (Si)-1.0000
Sulfur (S)-0.0300
PhOsphorus (P)-0.0450
Nickel (Ni)9.000012.0000
Manganese (Mn)-2.0000
Chromium (Cr)17.000019.0000
(Cb)-1.1000
Carbon (C)0.04000.1000

ASTM A249/A249M Type 347H Material Mechanical Properties

This ASTM A249/A249M covers ferritic/austenitic stainless steel welded and heavily cold worked tubes for general corrosive service, heat exchangers, condensers, heat treatment special and other similar applications. ASTM A249/A249M Type 347H is typically used within a range of temperatures of −450°F (−268°C) and higher.

The mechanical properties of the ASTM A249/A249M Type 347H steel are as follows:

YieldRp0.2 ≤ 219 (MPa)
TeileRm≤ 451 (MPa)
ImpactKV/Ku11(J)
ElongationA12%
Reduction in cross section on fractureZ44%
As-Heat-Treated ConditionSolution and Aging, Annealing, Ausaging, Q+T,etc
Brinell hardness (HBW)344

ASTM A249/A249M Type 347H Material Thermal Properties

The thermal performance parameters of the ASTM A249/A249M Type 347H steel are as follows:

Temperature (°C)24341894
Modulus of elasticity (GPa)-877-
Mean coefficient of thermal expaion ×10-6/(°C)--34
Thermal conductivity (W/m·°C)-31.322.2
Specific thermal capacity (J/kg·°C)-344-
Specific electrical resistivity (Ω mm²/m)0.32--
Deity (kg/dm³)--433
Poisson’s coefficient, ν--233

ASTM A249/A249M Type 347H Material Machining Technology

Machinability is a measure of how easily a material can be cut, drilled, or finished using machine tools. ASTM A249/A249M Type 347H steel has a high machinability rating and can be easily cut, drilled, or finished using machine tools.