Product introduction 

Boiler and pressure vessel steel plates are specialized medium-thick steel plates used to manufacture boiler pressure-bearing components (such as drums, furnace bladders, and water-cooled wall tubes) and pressure vessel components (such as shells, heads, and flanges). The core requirements for these steel plates are to maintain excellent mechanical properties, Weldable, and structural stability over long periods of time under specific temperature and pressure (even corrosive conditions) to ensure safe equipment operation and avoid major accidents such as explosions and leaks due to material failure.

Core features

1. A balance of high strength and high toughness: To withstand long-term high pressure, sufficient tensile strength and yield strength are required. To avoid brittle fracture at low temperatures or under impact, excellent low-temperature impact toughness is required (for example, meeting impact energy standards at -40°C and -60°C).

2. Good Weldable: Pressure-bearing components are often manufactured by welding, so the steel plate must have low weld crack susceptibility (for example, controlled carbon equivalent value (CEV) and weld crack sensitivity index (Pcm)). The performance of the weld joint must be no less than that of the parent material.

3. Stable metallurgical structure: Grain size must be strictly controlled (to avoid coarse grains that reduce toughness), and the presence of harmful microstructures (such as martensite and widmanstattenite) is prohibited. A stable microstructure is typically dominated by ferrite, pearlite, and bainite.

4. Strict internal quality: Internal defects that affect strength (such as pores, inclusions, and delamination) are not permitted. Ultrasonic testing (UT) and magnetic particle testing (MT) must be performed to achieve a high level of flaw detection (such as Level I or II in GB/T 2970).

5.High and low temperature resistance: According to different usage conditions, it is divided into "medium temperature creep resistance type" (such as boiler steel, which needs to resist creep deformation under long-term high temperature) and "low temperature toughness type" (such as low temperature storage tank steel, which needs to maintain toughness below -40°C).

Grade

Chemical properties (taking mainstream brand Q345R as an example)

Specification range

Thickness (t): Typically 6mm-200mm (thick plates require normalizing/tempering heat treatment to ensure uniform core properties);

Width (W): 1500mm-4800mm (wider plates can be customized based on equipment diameter to reduce weld seams);

Length (L): 6000mm-18000mm (longer plates can be used to manufacture large heads or shells, reducing the need for splicing);

Delivery Condition: Mainly "normalized" (for grain refinement and uniform tiny structure). Thick plates or low-temperature steels (such as 09MnNiDR) require "normalizing and tempering," while high-temperature alloy steels (such as 15CrMoR) require "tempering" (quenching and tempering).

Application areas

Energy: Power plant boilers (steam drums, water walls), nuclear reactor pressure vessels, and long-distance oil and gas pipelines (thick-wall tube billets);

Chemical: Reactors, heat switch, synthesis towers (such as hydrogenation towers in fertilizer plants), and acid and alkali storage tanks;

Cryogenic: LNG (liquefied natural gas) storage tanks, liquid nitrogen/liquid oxygen storage tanks, and ethylene crackers;

Other: Large pressure-bearing equipment (such as autoclaves and submersible pressure hulls).