Related Material — 67.3% match
based on chemical composition and mechanical property overlap.
GB/T 1591 Q690ME (GB/T 1591:2018) and GB/T 1591 Q550MD (GB/T 1591:2018) are both steel grades.
Both fall under the Structural Steel category.
GB/T 1591 Q690ME is typically used for general structure for engineering (plates, strips, bars and sections), while GB/T 1591 Q550MD is commonly used for general structure for engineering (plates, strips, bars and sections).
GB/T 1591 Q690ME is defined under Guobiao Standards (GB/T), originating from China, while GB/T 1591 Q550MD is defined under Guobiao Standards (GB/T), originating from China.
As per chemical composition, GB/T 1591 Q690ME vs GB/T 1591 Q550MD is a 97.2% match.
As per mechanical properties, the match is 7.4%.
Combined, this makes them a related material overall at 67.3%.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property
GB/T 1591 Q690ME
GB/T 1591 Q550MD
Tensile Strength
770-940 MPa
670-830 MPa
Yield Strength
>=690 MPa
>=550 MPa
Elongation
>=14%
>=16%
Condition
Thermomechanical processed (TMCP), nominal thickness or diameter up to 16 mm (tensile strength: up to 40 mm)
Thermomechanical processed (TMCP), nominal thickness or diameter up to 16 mm (tensile strength: up to 40 mm)
Typical Applications
GB/T 1591 Q690ME
General structure for engineering (plates, strips, bars and sections)
GB/T 1591 Q550MD
General structure for engineering (plates, strips, bars and sections)
Can GB/T 1591 Q690ME Be Substituted With GB/T 1591 Q550MD?
GB/T 1591 Q690ME and GB/T 1591 Q550MD share some compositional similarity but differ enough that substitution should not be assumed. Review the differences above carefully, and consult the applicable standard or a metallurgist before using one in place of the other.
What is the difference between GB/T 1591 Q690ME and GB/T 1591 Q550MD?
Both grades share a similar composition profile; see the specification table above for the exact chemistry and mechanical property values.
Can GB/T 1591 Q690ME be substituted with GB/T 1591 Q550MD?
GB/T 1591 Q690ME and GB/T 1591 Q550MD share some compositional similarity but differ enough that substitution should not be assumed. Review the differences above carefully, and consult the applicable standard or a metallurgist before using one in place of the other.