Comparing Mechanical Properties: S235J0 and DX51

The specifications, mechanical properties, and chemical composition of S235J0 and DX51 are compared as follows:

1. Specifications:
– S235J0: This is a non-alloy structural steel grade defined in the EN 10025-2 standard.
– DX51: This is a galvanized steel grade defined in the EN 10326 standard.

2. Mechanical Properties:
– S235J0: It has a minimum yield strength of 235 MPa and a minimum tensile strength of 360-510 MPa. The elongation after fracture is 17-21%.
– DX51: The mechanical properties vary depending on the thickness and coating weight. A typical value for yield strength is around 280-320 MPa. The tensile strength is generally between 270-420 MPa, and the elongation after fracture is 22-26%.

3. Chemical Composition:
– S235J0: The main elements present in this steel grade are carbon (C), manganese (Mn), silicon (Si), phosphorus (P), sulfur (S), and trace amounts of nitrogen (N). The maximum percentages of these elements are 0.17% C, 1.4% Mn, 0.35% Si, 0.035% P, 0.035% S, and 0.012% N.
– DX51: The chemical composition of DX51, being a galvanized steel grade, mainly consists of iron (Fe), carbon (C), manganese (Mn), silicon (Si), phosphorus (P), and sulfur (S). The maximum percentages of these elements are 0.12% C, 0.6% Mn, 0.5% Si, 0.045% P, and 0.03% S.

In summary, S235J0 is a non-alloy structural steel with a higher yield and tensile strength compared to DX51, which is a galvanized steel grade. The chemical composition of these grades differs slightly, with S235J0 containing additional elements such as nitrogen, while DX51 mainly consists of iron and other typical elements found in galvanized steel.