Chemical composition and mechanical properties of ST37 seamless steel pipe
Hit：392026-02-12 15:37:58
Chemical composition and mechanical properties of ST37 seamless steel pipe
Execution standard: ST37 seamless steel pipe is mainly based on the German standard DIN 17100 (gradually replaced by EN 10025-1), and its corresponding new grade is S235JR.
Equivalent Chinese grade: In engineering applications, ST37 seamless steel pipe is often equivalent to China's Q235B steel grade, and the two are highly similar in performance and usage.
Delivery status: usually in hot-rolled state, with good weldability and cold working performance, widely used in fields such as mechanical manufacturing, building structures, and conveying pipelines.
In summary, ST37 seamless steel pipe is a low-carbon structural steel with excellent comprehensive performance. Its chemical composition is strictly controlled and its mechanical properties are stable. It is a widely used basic material in the industrial field.
Mechanical performance
The mechanical properties of ST37 seamless steel pipes are mainly based on yield strength and tensile strength as core indicators, with specific values varying depending on thickness and grade:
Explanation of the Range of Performance Index Values
The yield strength (ReL) ≥ 235 MPa is the universal lower limit for ST37-2 and St37-3, with some standards (such as St37-2G) specifying ≥ 215 MPa.
Tensile strength (Rm) 360-510 MPa. When the thickness is ≤ 16mm, the upper limit of tensile strength is 510 MPa; When the thickness is greater than 16mm, the lower limit may drop to 340MPa.
The elongation at break (A) is ≥ 20% -25%. When the thickness is thinner, the elongation is higher. For example, St37-3 requires ≥ 17% when the thickness is>3mm.
Impact energy (Akv) ≥ 27 J (0 ℃) is a clear requirement for St37-3. St37-2 usually does not require impact performance unless specifically ordered
Chemical composition
The chemical composition of ST37 series seamless steel pipes is mainly low-carbon, with the main element content range as follows (unit:%):
Carbon (C): usually controlled between 0.17% and 0.20%, with some standards having an upper limit of 0.21%.
Manganese (Mn): Generally 0.40% -1.20%, with some standards having upper limits of 1.4% or 1.60%.
Phosphorus (P): Strictly controlled, with an upper limit of ≤ 0.045% or ≤ 0.050%.
Sulfur (S): The upper limit is ≤ 0.045% or ≤ 0.050%.
Silicon (Si): The content is usually ≤ 0.55%, but some standards do not have mandatory regulations.
Nitrogen (N): The upper limit is ≤ 0.009%.
Regarding the chemical composition and mechanical properties of ST37 seamless steel pipes, it should be clarified that "ST37" is a general designation in the German DIN standard, which includes multiple specific designations such as St37-2, St37-3, etc. These grades have slight differences in chemical composition and mechanical properties, but they all belong to the category of carbon structural steel.
