Purlin roll forming machines withstand continuous loads, friction, and impacts during continuous cold forming. The choice of materials directly affects the equipment's strength, wear resistance, stability, and service life.A reasonable combination of materials for different components can satisfy mechanical performance requirements while also considering machinability and economy, laying the foundation for long-term reliable operation.
The primary consideration for the materials of the main structural components is strength and rigidity. The frame, base, support beams, and other load-bearing frames are typically made of high-quality carbon structural steel or low-alloy high-strength steel. These steels possess good tensile, compressive, and bending strength, maintaining shape stability under high-speed operation and roll forming impacts, reducing deformation and vibration. To ensure welding and processing quality, the selected steel should have good weldability and machinability, and stress-relief annealing should be performed when necessary to eliminate residual stress from the forming process.
Rollers are the core components of the forming process, and their materials must possess both high hardness and sufficient toughness. Rollers are commonly made of high-carbon chromium-molybdenum alloy steel or hardened tool steel. These materials, after heat treatment, achieve a deep hardened layer with sufficient surface hardness to resist repeated extrusion and sliding wear of the metal strip, while maintaining core toughness to prevent brittle fracture under impact loads. For applications with complex forming profiles or large batch sizes, surface strengthening processes can be used to further enhance wear resistance and extend roller replacement cycles.
The materials used for transmission and load-bearing components prioritize fatigue resistance and wear resistance. Spindles, gears, sprockets, and bearing housings are made of tempered alloy structural steel, ensuring sufficient strength and toughness while delaying fatigue crack initiation under cyclic loads. Gear surfaces can be carburized or nitrided to improve wear resistance and anti-galling capabilities. Rolling bearings are selected using bearing steel of appropriate grades based on load and speed to ensure precise rotation and low friction during high-speed operation.
Moving connections such as guide rails, sliders, and clamping mechanisms are often made of wear-resistant cast iron or hard chrome-plated steel. Cast iron possesses excellent shock absorption and machinability, making it suitable for manufacturing bases that withstand reciprocating sliding. Hard chrome plating significantly enhances surface hardness and corrosion resistance, reducing wear and rust caused by dust and moisture.
Auxiliary structures such as protective covers, maintenance platforms, and connectors are mostly made of ordinary carbon steel or lightweight profiles, balancing strength and manufacturing cost. They are coated with anti-corrosion paint to withstand the humidity and contamination of the workshop environment. The electrical cabinet housing and internal supports are made of cold-rolled steel sheet with an insulating and anti-corrosion coating, protecting components from mechanical damage and preventing electromagnetic interference and moisture corrosion.
