I. Basic Definition
S275JOH is a low alloy high-strength structural steel under the European standard (EN 10025), widely used in construction, bridge and machinery manufacturing, characterised by high yield strength (≥275MPa) and good welding performance.
II. Naming rules and performance indexes
Naming meaning:
S: stands for 'structural steel' (Structural Steel);
275: indicates that the minimum yield strength of 275MPa;
JOH: identifies its specific impact toughness and processing properties ('J' for normal temperature impact, 'O'). JOH: identifies it as having specific impact toughness and processability ('J' for normal temperature impact, 'O' may identify a specific process or application, and 'H' may indicate hot forming or a specific strength grade).
Mechanical properties:
Yield strength: ≥275 MPa;
Tensile strength: 430-580MPa;
Elongation: ≥18% (reflecting the ductility of the material).
Third, the chemical composition
The chemical composition of S275JOH is strictly controlled, and the range of major elements is as follows (mass per cent):
Carbon (C): ≤ 0.20%;
Manganese (Mn): ≤ 1.50%;
Silicon (Si), phosphorus (P), sulfur (S): are controlled at a low level (such as P ≤ 0.035%, S ≤ 0.035%) to ensure weldability and corrosion resistance.
Fourth, the field of application
Building structure:
Load-bearing parts such as bridge supports, high-rise building frames, etc.
Machinery manufacturing:
Engineering machinery components, vehicle chassis and other areas that need to withstand dynamic loads.
Special scenes:
Complex environment (such as high humidity, corrosive media) under the anti-fatigue, corrosion-resistant structural components.
V. Process and standards
Execution standard: EN 10025 (European structural steel standard), covering hot rolling, controlled rolling and other process requirements.
Delivery status: Usually supplied in hot rolled or controlled rolled condition, and can be directly welded, cut or cold processed.
VI. Differences with similar materials
Comparison of S275JR:
S275JOH has better impact toughness ('JOH' marking) and is suitable for more demanding dynamic loading scenarios, while S275JR is a conventional structural steel, focusing on basic strength.
Comparison with Q355B (GB):
S275JOH has a slightly lower yield strength than Q355B (355 MPa), but better welding properties and low temperature toughness.
Summary
S275JOH is a European standard low alloy high strength structural steel, with high yield strength, excellent welding performance and fatigue resistance as its core advantages, widely used in construction, bridges and machinery manufacturing fields. The 'JOH' designation in its designation reflects specific requirements for impact toughness and processing, differentiating it from common structural steels such as S275JR.
