To ensure the smooth execution of the P275N steel plate order, our company recently accompanied the customer to the steel mill for an on-site inspection of production and quality control procedures.
The inspection focused on the actual manufacturing status of the P275N plates and verification of compliance with EN 10028-3.
P275N Steel Plate Production Status
The inspected material was P275N normalized pressure vessel steel plate, produced from continuous casting slabs. The production route followed standard mill practice, including hot rolling and normalizing heat treatment. Plate thickness, rolling temperature, and cooling conditions were recorded during production.
The customer reviewed production records and plate identification markings to confirm heat number traceability from steelmaking to finished plates.
Key Production Processes Observed
During the factory visit, the customer inspected the following process steps directly on site:
Converter steelmaking and ladle refining
Slab reheating and rough rolling
Finish rolling and thickness control
Normalizing heat treatment furnace
Plate leveling, cutting, and stamping
Mill engineers explained how process parameters are controlled to ensure stable mechanical properties for pressure vessel use.
Chemical Composition Test Results
Samples were taken according to standard sampling procedures. Chemical composition was tested in the mill laboratory.
Table 1: Chemical Composition of P275N Steel Plate (Heat Analysis, wt.%)
| Element | C | Si | Mn | P | S | Al |
|---|---|---|---|---|---|---|
| EN 10028-3 Limit | ≤0.20 | ≤0.40 | 0.80–1.50 | ≤0.025 | ≤0.015 | ≥0.020 |
| Measured Value | 0.15 | 0.31 | 1.27 | 0.020 | 0.007 | 0.041 |
All measured values met the standard limits and were recorded in the mill test report.
Mechanical Testing at Mill Laboratory
Mechanical tests were carried out on normalized test pieces prepared from the same heat and rolling batch.
Table 2: Mechanical Properties of P275N Steel Plate
| Test Item | Requirement | Actual Result |
|---|---|---|
| Yield Strength (MPa) | ≥275 | 308 |
| Tensile Strength (MPa) | 410–560 | 448 |
| Elongation (%) | ≥22 | 26 |
| Impact Test | As specified | Conforming |
The results indicate stable strength and adequate ductility suitable for pressure vessel fabrication.
Ultrasonic Testing and Dimensional Inspection
Finished plates underwent 100% ultrasonic testing in accordance with the specified acceptance level. Thickness, width, length, and flatness were checked during final inspection.
No reportable internal defects were found, and dimensional deviations remained within allowable tolerances.
Customer Review and Confirmation
The customer reviewed production logs, laboratory test records, and UT reports on site. After completing the inspection, the customer confirmed that the P275N steel plates comply with EN 10028-3 and order requirements and approved the continuation of the production and delivery schedule.
We will continue to follow standard mill quality procedures to ensure traceability, consistency, and reliable performance of pressure vessel steel plates supplied to our customers.
