What are the differences between heat-resistant steel castings and ordinary steel castings?

Overview of heat-resistant steel castings and ordinary steel castings
Both heat-resistant steel castings and ordinary steel castings are metal parts formed by steel during the casting process, and are widely used in various industrial production and daily life. Heat-resistant steel castings are specially designed for special working environments such as high temperature and high pressure, and their performance and material composition have higher high temperature resistance, oxidation resistance, corrosion resistance and other characteristics. Compared with ordinary steel castings, heat-resistant steel castings can maintain their mechanical properties and stability under extreme working conditions, while ordinary steel castings are suitable for working environments within the normal temperature range.

Composition difference between heat-resistant steel castings and ordinary steel castings
An important difference between heat-resistant steel castings and ordinary steel castings is their alloy composition. Heat-resistant steel usually contains a higher proportion of chromium, nickel, molybdenum, titanium and other elements, which can effectively enhance the high temperature resistance and oxidation resistance of steel. The alloy composition of ordinary steel castings is relatively simple, mainly based on iron, with a high carbon content, suitable for use in normal temperature environments.
The composition of heat-resistant steel is designed to maintain strength and hardness at high temperatures, while ordinary steel castings may lose strength, or even deform or damage at high temperatures. Due to the special composition of heat-resistant steel, its manufacturing cost is relatively high, but it can provide longer service life and higher working stability.

Comparison of the temperature resistance of heat-resistant steel castings with ordinary steel castings
One of the main advantages of heat-resistant steel castings is its excellent high temperature resistance. Ordinary steel castings will experience significant performance degradation due to the influence of temperature under long-term high temperature environment, and even become brittle under some extreme conditions. In contrast, heat-resistant steel castings can maintain high strength and hardness in high temperature environments and are suitable for use in high temperature working environments, such as thermal power plants, steel smelting, engine parts and other fields.
The temperature resistance of heat-resistant steel castings comes from its high alloy composition, which can effectively avoid oxidation, corrosion and deformation at high temperatures. Ordinary steel castings, due to the lack of support of this high-temperature alloy, can usually only work at temperatures below 300°C, and physical properties are prone to changes after exceeding this temperature.

Key Differences Between Heat-Resistant Steel Castings and Ordinary Steel Castings

Comparison of mechanical properties of heat-resistant steel castings with ordinary steel castings
Mechanical properties are the key factor in determining whether a steel casting is suitable for a specific job. Heat-resistant steel castings must not only meet the strength requirements in high-temperature environments, but also have good tensile strength, hardness, toughness and other characteristics. The mechanical properties of ordinary steel castings are more dependent on the performance at normal temperatures. Once the temperature is too high, the strength and hardness of ordinary steel will drop rapidly.
Heat-resistant steel castings are usually high in strength and can maintain stability for a long time in high-temperature environments. Its resistance to thermal fatigue and thermal cracking is relatively good, and it is suitable for applications under high-temperature alternating loads. Ordinary steel castings do not have such strong resistance to thermal fatigue, so they are prone to cracks or ruptures in environments with drastic temperature changes.

Comparison of oxidation resistance of heat-resistant steel castings with ordinary steel castings
Another major advantage of heat-resistant steel castings is their excellent oxidation resistance. In high-temperature environments, the surface of steel easily reacts with oxygen to form an oxide layer, resulting in a decrease in material performance. Heat-resistant steel castings effectively improve their oxidation resistance by containing elements such as chromium and nickel. Even at high temperatures, the surface of heat-resistant steel castings is not easy to form a thick oxide layer, and can maintain good performance.
Ordinary steel castings are more likely to oxidize at high temperatures, especially ordinary steel with a high carbon content. They will quickly form an iron oxide layer at high temperatures, causing corrosion on the steel surface and further affecting the mechanical properties of the material.

The difference between the corrosion resistance of heat-resistant steel castings and ordinary steel castings
The difference in corrosion resistance between heat-resistant steel castings and ordinary steel castings is also a significant feature. The addition of elements such as chromium, molybdenum, and nickel in heat-resistant steel castings enables them to resist corrosion from high temperatures and chemical media. In some harsh environments such as acidic atmospheres, seawater environments, and chemical reactions, the corrosion resistance of heat-resistant steel castings is better than that of ordinary steel castings, and they can maintain a longer service life.
Ordinary steel castings usually lack resistance to chemical corrosion, especially in humid or acid-base environments, and are prone to corrosion, resulting in a rapid decline in their performance.

Comparison of the cost of heat-resistant steel castings with ordinary steel castings
Because heat-resistant steel castings require the use of more alloying elements, their production cost is relatively high. In contrast, ordinary steel castings have a lower cost due to their simple composition and relatively mature production process. Although the manufacturing cost of heat-resistant steel castings is high, their excellent high temperature resistance, oxidation resistance, and corrosion resistance enable them to have a longer service life and lower maintenance costs in applications under high temperature and harsh environments.
In the long run, although the initial investment of heat-resistant steel castings is high, it can improve the reliability of equipment under extreme working conditions, reduce maintenance costs and downtime, which is very valuable for some high-end industrial applications.

Application scope of heat-resistant steel castings and applicable scenarios of ordinary steel castings
The main application areas of heat-resistant steel castings include high-temperature equipment components, energy industries (such as boilers, burners, steam generators, etc.), automotive engines, aerospace components, metallurgical equipment, etc. Due to its high temperature resistance, oxidation resistance, corrosion resistance and other characteristics, heat-resistant steel castings are widely used in components that need to work in harsh environments such as high temperature and high pressure for a long time.
Ordinary steel castings are more suitable for use in normal temperature environments, such as mechanical structures, building components, home appliance components, etc. Although they can meet the use requirements well in some light load and low temperature environments, they cannot provide sufficient protection for high temperature and high load applications.