Below is a detailed comparison of the chemical composition and mechanical properties for the grades Q275A, Q275B, Q275C, and Q275D according to the GB/T 700 standard.
Explanation of Key Parameters:
- Carbon (C): Determines the steel's hardness and strength.
- Manganese (Mn): Improves strength and toughness.
- Silicon (Si): Enhances strength and flexibility.
- Phosphorus (P) and Sulfur (S): Impurities that should be kept low to avoid brittleness.
- Yield Strength: The stress at which material starts to deform plastically.
- Tensile Strength: The maximum stress the material can withstand while being stretched.
- Elongation: The material's ability to deform plastically before breaking.
- Impact Test Temperature: The temperature at which the steel's impact toughness is tested.
Q275 has three grades of steel plates, and these grades' properties and compositions give them different degrees of toughness, suitable for different environments and applications. Q275C and Q275D have higher toughness and are more suitable for cold climates, while Q275A and Q275B are suitable for general use.
Q275 Steel Plate grades have different properties, each suitable for different applications.(1) Q275A grade low alloy carbon plate has the basic strength of steel plate and moderate toughness, which is very suitable for general structural use.
(2) Q275B has better impact resistance at 0°C and is suitable for slightly colder environments, such as mild climate buildings.
(3) Q275C can withstand impact at -20°C and is used for building structures and machinery in colder areas.
(4) Q275D has the highest toughness at -40°C and is best suited for extremely cold climates, ideal for outdoor infrastructure and heavy equipment in polar or sub-polar regions. These applications take full advantage of the specific mechanical properties and impact resistance of each grade.
Q275A Low Alloy Carbon Plate: First of all, this grade of steel plate is simple to weld, but the temperature and time of cooling need to be controlled to avoid residual stress as much as possible. Standard methods for normal cutting of steel plate are also applicable, and appropriate cutting speed needs to be ensured. Forming can be completed without special precautions, but uniform application of force is required.
Q275B: Q235b uses similar welding techniques to Q275A, but requires attention to interpass temperature. Ensure clean edges during cutting to prevent micro cracking. Forming may require post-forming heat treatment to maintain impact resistance.
Q275C: Careful control of welding temperature is required for use in cooler environments. Cold cutting methods are preferred to minimize the heat affected zone. Slow forming speeds and controlled environments are recommended.
Q275D: Welding requires the highest control, including preheating and post-weld treatment to maintain toughness at -40°C. Cold cutting is strongly recommended; if hot cutting is used, immediate post-cutting treatment is performed. Very careful operation and slow forming speeds are essential.
About Henan Houming Industrial Co., Ltd.: We are a manufacturer specializing in deep processing of prefabricated houses, silicon steel, weathering steel and wear-resistant plates. Houming adheres to the business philosophy of "seeking truth and being pragmatic" and is committed to providing customers with high-quality products and services. Through continuous technological innovation and process improvement, we have established a good reputation in the industry and won the trust and support of our customers.
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