15CrMoR steel plate is a material with good heat resistance, hydrogen corrosion resistance, and high mechanical strength, widely used in industries such as petroleum, chemical, power plants, boilers, and pressure vessels. Its application temperature range mainly depends on the material's mechanical properties, corrosion resistance, and weldability.

1. Mechanical Properties: 15CrMoR steel plate has high tensile strength, yield strength, and good elongation and reduction of area, which allows the material to maintain its superior mechanical properties even at high temperatures. Therefore, the application temperature range of 15CrMoR steel plate can reach relatively high levels.

2. Corrosion Resistance: 15CrMoR steel plate has good heat resistance and oxidation resistance, enabling it to resist oxidation and corrosion at elevated temperatures, ensuring the long-term stable operation of equipment. This gives 15CrMoR steel plate high application value in high-temperature corrosive environments.

3. Weldability: 15CrMoR steel plate has good weldability, ensuring that the strength and toughness of welded joints meet requirements. In practical applications, depending on the welding process requirements, 15CrMoR steel plate can be used in various welded structures, thereby expanding its application temperature range.

In summary, the application temperature range of 15CrMoR steel plate is relatively broad, and it can be used within a temperature range of -20°C to 575°C. In practical applications, reasonable selection of steel plate thickness, specifications, and welding processes based on specific design requirements and construction conditions can ensure the safety, reliability, and durability of the structure. It is important to note that in high-temperature environments, the application of 15CrMoR steel plate requires attention to changes in the material's mechanical properties, corrosion resistance, and weldability to ensure its safe operation under high-temperature conditions.