What Are Boiler Steel Plates?

Boiler steel plates are essential materials used to make key boiler parts, such as shells, drums, end covers, and supports. These plates are often exposed to high temperature and pressure. At the same time, they face corrosion, fatigue, and impact during use.

If the plates fail, serious accidents may occur. So, they must meet strict safety and performance standards.

Classification by Material

Boiler steel plates are grouped by material into:

Special carbon steel plates

Low-alloy heat-resistant steel plates

To ensure good quality, the following are required:

Strict control of harmful elements like sulfur and phosphorus

Proper removal of non-metallic inclusions during smelting

Uniform microstructure and grain size (usually between levels 3 to 7)

Good surface condition, with no internal defects

High mechanical strength at room and high temperatures

According to GB/T713-2014, smelting must be done using oxygen converters or electric furnaces, followed by external refining. A compression ratio of at least 3 is required during hot rolling.

Classification by Working Environment

1. Plates for Room and Medium Temperature (Below Creep Temperature)

These are made from:

Carbon steel

Carbon-manganese steel

Carbon-manganese-silicon steel

Common grades:

GB/T713-2014: Q245R, Q345R

Older standard (GB/T713-1997): 20g, 22Mng, 16Mng, 19Mng

ASME: SA-515, SA-299

Applications: Drums, end covers, and other parts exposed to medium temperature.

Required properties:

High strength at room temperature

Good toughness and low notch sensitivity

Good weldability and cold formability

Strong resistance to aging and cracking

2. Plates for High Temperature (Above Creep Temperature)

These are made from heat-resistant low-alloy steel like:

Chromium-molybdenum steel (15CrMoR)

Chromium-molybdenum-vanadium steel (12Cr1MoVR)

Chromium-molybdenum-tungsten steel (Gr22, Gr91, Gr911, Gr122)

Applications: High-temperature headers, steam pipes, and other parts under extreme heat.

Required properties:

High strength and ductility at high temperatures

Good resistance to heat and oxidation

Stable structure during use

Good weldability and cold bending ability

Main Features of Boiler Steel Plates

Boiler steel plates must have:

High yield strength at normal and high temperatures

Strong toughness to avoid brittle failure

Low sensitivity to aging and notches

Good welding performance

Uniform and clean microstructure (no cracks or white spots)

Production Process

To meet quality demands, the following advanced processes are used:

Hot metal desulfurization before smelting

Clean steel production in converters

Outside-furnace refining to remove impurities

RH vacuum degassing to reduce gases like oxygen, nitrogen, and hydrogen

Continuous casting for defect-free slabs

Controlled rolling and cooling for even grain size

Precise heat treatment to ensure proper mechanical properties

With the rise of ultra-supercritical boilers, the demand for advanced boiler steel plates continues to grow. China has adopted modern techniques to meet these requirements.

Boiler Steel Plate Summary Form