Cold Heading Quality wire (CHQ wire) is a high-performance metal material specially used in cold forming process (such as cold heading and cold extrusion). Simply put, it is like the "super plasticine" of the industry-without heating, the metal wire "flows" in the mold through huge pressure, and eventually becomes bolts, nuts or various Complex shape parts. 1. Core features: Why is it different from ordinary steel wire? Ordinary steel wire if forced flat, easy to produce cracks or fracture. The CHQ wire must have the following "hard core" qualities: · High plasticity (plasticity): able to withstand severe deformation without cracking. Excellent surface quality: the surface can not have scratches, cracks or strain, because any small defects in the cold heading moment will be magnized into a fatal crack. · Pure composition: internal impurities (such as sulfur, phosphorus) content is very low, uniform organization, to ensure that each inch of wire strength and toughness. Dimensional accuracy: The tolerance of the wire diameter is usually controlled at the micron level to ensure that the cold heading machine can enter the high-speed operation smoothly. 2. Production process: how to refine into a roll of CHQ wire? A typical production process typically includes the following key steps: Selection of raw materials: selection of high-quality low carbon steel (such as C10C), medium carbon steel (such as 35K) or alloy steel (such as 10B21, SCM435) hot-rolled wire rod. Pickling and phosphating (Pickling & Coating): remove the oxide scale on the surface with acid and apply a phosphating film or lubricant. This layer of "coat" is very critical, it can reduce mold friction during cold heading. · Fine drawing (Drawing): through the wire drawing machine to draw the coarse wire rod to the target diameter, this step will improve the strength of the material. · Annealing (Annealing): If the material is too hard, it needs to enter the annealing furnace for heat treatment to make it soft and restore plasticity. Finished product inspection: including metallographic analysis (to see the internal structure), tensile test and the most important cold upset test (flattening a section of wire to 1/3 of the original height to observe whether it is cracked). 3. Application scenario: what has it become? Cold heading wire is the "food" of fastener industry ". Almost all the metal connections around you come from this: · Automotive industry: engine bolts, hub bolts. · Construction industry: high-strength bolts, planting bar bolts. Electronics/home appliances: mobile phone micro screws, air conditioning compressor parts. · Aerospace: Special high-strength rivets. 4. Industry Blackword: What is "spheroidizing annealing"? When communicating with customers, annealing status is often mentioned. Spheroidizing annealing (Spheroidizing) is the most high-end process, it can make the carbide inside the steel into a ball, providing extreme plasticity, suitable for the production of complex shapes of non-standard parts (shaped parts). What Is Cold Heading Quality (CHQ) Wire? Cold Heading Quality Wire (CHQ Wire) is a high-performance metallic material specifically designed for cold forming processes, such as cold heading and cold extrusion. To put it simply, it acts like the "industrial version of high-strength Play-Doh"-it allows metal wire to "flow" within a mold under immense pressure without being heated, eventually transforming into bolts, nuts, or various complex-shaped parts. 1. Core Characteristics: Why Is It Different from Ordinary Steel Wire? While ordinary steel wire is prone to cracking or breaking if forcibly flattened, CHQ wire must possess the following "hardcore" qualities: ·Extremely High Plasticity (Formability): It can withstand severe deformation without cracking. ·Excellent Surface Quality: The surface must be free of scratches, cracks, or pull marks, as any microscopic defect will be magnified into a fatal fracture during the instantaneous cold heading process. ·Pure Composition: It has an extremely low content of internal impurities (such as sulfur and phosphorus) and a uniform microstructure, ensuring consistent strength and toughness throughout every inch of the wire. ·Dimensional Precision: Wire diameter tolerances are typically controlled at the micron level to ensure smooth feeding into high-speed cold heading machines. 2. Production Process: How Is a Coil of CHQ Wire Made? A typical production flow involves the following key steps: ·Raw Material Selection: High-quality hot-rolled wire rods made of low-carbon steel (e.g., C10C), medium-carbon steel (e.g., 35K), or alloy steel (e.g., 10B21, SCM435) are selected. ·Pickling & Coating: Acid is used to remove surface scale, followed by the application of a phosphate coating or lubricant. This "outer layer" is crucial for reducing mold friction during cold heading. ·Fine Drawing: A drawing machine pulls the thick wire rod down to the target diameter, a step that increases the material's strength. ·Annealing: If the material becomes too hard, it enters an annealing furnace for heat treatment to soften it and restore its plasticity. ·Finished Product Inspection: This includes metallographic analysis (examining internal structures), tensile testing, and the critical Cold Upsetting Test (compressing a section of wire to 1/3 of its original height to check for cracks). 3. Application Scenarios: What Does It Become? CHQ wire is the "bread and butter" of the fastener industry. Nearly all metal connectors around you originate from it: ·Automotive Industry: Engine bolts, wheel bolts. ·Construction Industry: High-strength bolts, chemical anchors/rebar bolts. ·Electronics/Appliances: Micro-screws for mobile phones, air conditioner compressor parts. ·Aerospace: Special high-strength rivets. 4. Industry Jargon: What Is "Spheroidizing Annealing "? When communicating with clients, the annealing state is frequently discussed. Spheroidizing Annealing is a high-end process that transforms the carbides within the steel into a spherical shape. This provides ultimate plasticity, making it ideal for producing non-standard (special-shaped) parts with complex geometries.