In global procurement and design, understanding the equivalency between
Chinese standard Q245R and American
ASTM A515 Gr.65 steel plates is crucial for cost optimization and supply chain flexibility. While they serve similar purposes in pressure equipment, direct substitution requires careful technical evaluation.
Key Comparison: Chemical Composition & Properties
Both grades are carbon-manganese-silicon steels for pressure vessels, but differences exist:
Q245R (GB/T 713): This is a normalized steel with a maximum carbon content typically around 0.20%. It is specifically designed for ambient and medium-temperature service, with mandatory impact toughness requirements at room temperature.
A515 Gr.65 (ASTM A515): This grade is supplied in normalized or stress-relieved condition, with a higher maximum carbon content (up to 0.24%). It is intended for intermediate and higher-temperature service (up to ~425°C). Notch toughness is not a default requirement unless specified.
Equivalency Status and Primary Substitution Considerations
There is no direct, universally accepted "equivalent" between the two grades. Substituting one for the other is a design change that requires formal approval. Key considerations include:
Governing Design Code: The project's construction code (ASME, GB, or others) is paramount. A material must be listed and qualified within that specific code. SA-515 Gr.65 is an ASME code stamp material; Q245R is not, unless specifically accepted by the jurisdiction and the Authorized Inspector (AI).
Temperature Service: Verify the design temperature. A515 Gr.65 has established allowable stress values at elevated temperatures in ASME codes. The allowable stresses for Q245R at elevated temperatures must be carefully evaluated against the design requirements.
Impact Toughness: For low-temperature or shock-prone applications, the guaranteed impact properties of Q245R may be an advantage, whereas A515 Gr.65 would require supplementary testing.
Certification: A valid Chinese Mill Certificate for Q245R must be thoroughly reviewed against the project's material requisition, which is typically based on ASTM/ASME specifications.
While Q245R and A515 Gr.65 share similar application fields, they are not automatically interchangeable. Substitution requires a case-by-case engineering assessment, focusing on the design code, temperature limits, and mechanical property requirements. Always consult with the responsible design engineer and code authority before making a substitution decision.
