Alloy Steel 13CrMo4-5 Round Bars / 13CrMo4-5 Bar / 13CrMo4-5 Rods / 13CrMo4-5 Rings

Product Description

13CrMo4-5 (Material Number 1.7335) is a high-temperature structural alloy steel used extensively in the power generation, chemical, and petrochemical industries. It is the European equivalent to the widely known ASTM A182/A335 Grade P11/F11.

It is primarily valued for its resistance to hydrogen attack and its high "creep" strength”the ability to resist deformation under constant stress at elevated temperatures.

1. Technical Standards

This grade is defined under several key European standards depending on the product form:

• EN 10273: Hot rolled weldable steel bars for pressure purposes.

• EN 10222-2: Steel forgings for pressure purposes (Rings and larger bars).

• EN 10028-2: Steel flat products for pressure purposes.

• Equivalent Grade: ASTM A182 F11 / ASTM A335 P11.

2. Chemical Composition (%)

The presence of Chromium (Cr) and Molybdenum (Mo) provides the necessary oxidation resistance and high-temperature stability.

3. Mechanical Properties (at Room Temp)

While 13CrMo4-5 is designed for heat, its baseline mechanical properties in the Normalized & Tempered (NT) condition are:

• Tensile Strength: 450 “ 600 MPa.

• Yield Strength: ‰ 290 MPa (for thicknesses $\le 60$ mm).

• Elongation: ‰ 22%.

• Impact Energy: ‰ 31 J (at room temperature).

4. Key Features & Performance

• Operating Range: Efficiently maintains its structural integrity at service temperatures up to approx. 550C (1022F).

• Creep Rupture Strength: Significantly higher than standard carbon steels or the P1 grade mentioned previously.

• Corrosion Resistance: The Chromium content offers improved resistance to atmospheric corrosion and mildly acidic environments in refineries.

• Weldability: It is weldable, but because it is an alloy steel, pre-heating and Post-Weld Heat Treatment (PWHT) are mandatory to prevent the formation of brittle martensite in the heat-affected zone.

5. Product Forms & Applications

• Round Bars & Rods: Typically used to manufacture high-strength bolts, studs, and fasteners for high-pressure flanges and valves.

• Forged Rings: Used as blanks for the production of flanges, heat exchanger tube sheets, and reinforcement rings in pressure vessels.