hot-rolled steel plate is a fundamental and versatile industrial material, serving as the backbone for construction, manufacturing, and infrastructure projects worldwide. Produced by heating large steel slabs above their recrystallization temperature (typically over 1700°F / 925°C) and then rolling them to a specific thickness, this process results in a robust and economically efficient product.

Grade Designation: Understanding "Q195"

The name "Q195" follows the Chinese standard GB/T 700-2006, which is commonly used internationally alongside standards like ASTM A36. The designation breaks down as follows:

195: Indicates the minimum yield strength of 195 MPa (Megapascals).

This means the material is guaranteed to have a yield strength of at least 195 MPa, defining its fundamental mechanical capability.

Key Characteristics & Properties

Good Strength and Ductility: With a yield strength of 195 MPa and a tensile strength of 315-430 MPa, Q195 offers a good balance for applications requiring moderate strength and the ability to be bent or formed without cracking.

Excellent Formability: Its relatively low carbon content makes it highly ductile. It can be easily cold-worked, bent, stamped, and rolled into various shapes, making it ideal for fabrication.

Superior Weldability: Q195 can be welded using all common methods (SMAW, GMAW, etc.) without pre-heating or post-weld heat treatment under most conditions, simplifying the manufacturing process.

Cost-Effective: As a widely produced, general-purpose steel, Q195 is one of the most economical choices for a vast range of applications, providing excellent value.

Manufacturing Process: Hot-Rolling

Q195 steel plate is produced through the hot-rolling process. This involves:

Heating large steel slabs above their recrystallization temperature (typically over 1100°C / 2000°F).

Passing the heated slab through a series of rollers to reduce its thickness and achieve the desired dimensional tolerances.

Cooling the plate to room temperature.

This process results in a plate with a characteristic slightly scaled surface, improved toughness, and reduced internal stresses compared to cold-rolled products.

Common Applications

Q195 Hot-rolled steel plate is versatile and found in a multitude of industries, including:

Construction: For non-critical structural parts, brackets, and base plates.

Automotive Manufacturing: Body panels, chassis components, and various brackets and supports.

General Manufacturing: Machine covers, guards, cabinets, and housings.

Fabrication and Machinery: As a base material for a wide array of fabricated parts, frames, and agricultural equipment.

Appliances: Components for household and industrial appliances.

Pipe and Tube Manufacturing: Used as a starting material for forming welded pipes and tubes.

Advantages Summary

Economic Efficiency: Provides essential mechanical properties at a low cost.

Ease of Fabrication: Simplifies manufacturing processes like cutting, welding, and bending.

Wide Availability: Readily available in various thicknesses and sizes from steel suppliers worldwide.

Reliability: A proven and trusted material for light to moderate-duty applications.

Comparison with Similar Grades

Q235: Has a higher yield strength (235 MPa) and is used for more structurally demanding applications.

Q275: Offers even higher strength but lower formability.

ASTM A36: A very similar and often directly comparable American standard grade.

In conclusion, Q195 Hot-Rolled Steel Plate is a fundamental, versatile, and economical engineering material. Its combination of adequate strength, exceptional formability, and ease of welding makes it a first-choice material for countless fabricators and manufacturers across the globe.