Carbon cold rolled and hot rolled wire rod
Low-carbon SWRCH6 to 16A series steels are non-heat-treated materials used for cold heading and cold extrusion. These are primarily employed in the production of fasteners with lower strength requirements. Due to the high deformation involved in cold heading, especially when the deformation exceeds one-third, these materials must undergo annealing. It is recommended that customers choose low-carbon grades such as SWRCH6A, particularly when large cold heading deformations are required. Additionally, selecting wire material specifications similar to the final product dimensions helps reduce drawing deformation and minimize work hardening effects.
Free return cold rolled steel and hot rolled wire rod
In 2004, Maanshan Iron & Steel Co., Ltd. participated in the National 863 Program titled "Research on High Performance and Low Cost Cold Rolled Steel" (2003AA331030). The goal was to develop an independent, cost-effective technology for producing cold heading steel wire in China, focusing on online softening techniques.
High-strength fasteners of class 8.8 and above are typically made from medium carbon or alloyed steels. The manufacturing process includes hot rolling, spheroidizing annealing, cold drawing, forming, and quenching and tempering. Spheroidizing annealing is essential to ensure sufficient plasticity for cold heading, which can involve up to 70–80% total deformation. Therefore, the raw material's hardness should be kept low, generally not exceeding HRB82. This step is currently the most time-consuming and energy-intensive in fastener production, often taking 12–24 hours in batch or continuous furnaces. The industry seeks to simplify or eliminate this step to improve efficiency and reduce costs.
Ma Steel’s high-line technology incorporates the latest advancements in wire rod rolling, creating a unique production line with independent intellectual property rights. They have developed annealed SWRCH35K-M and CH35A-M hot-rolled wire rods, as well as SWRCH35K-MT and CH35A-MT for export to the US market. These products are suitable for manufacturing hexagonal bolts and similar fasteners. For those requiring large deformation, spheroidizing annealing is still necessary. For nuts, MFM-1 and MFM-3 hot-rolled wire rods were successfully developed for standard high-strength nuts, while MFM-2 eliminates both annealing and quenching/tempering, directly producing 8.8-grade nuts.
Non-regulated cold rolled steel and hot rolled wire rod
Non-tempered cold heading steel is mainly used for high-strength fasteners like 8.8, 9.8, and 10.9 grade bolts. Using this material eliminates pre-drawing annealing and post-bolting quenching/tempering, significantly streamlining the process. This reduces energy consumption, production time, and issues like oxidation, decarburization, and deformation caused by heat treatment, offering substantial economic and environmental benefits. Japan has already implemented mass production of such materials.
In 2005, Maanshan Iron & Steel Co., Ltd. took part in the National 863 Program “Research and Development of Non-tempered Steel Wire for Low Temperature Controlled Rolling and Controlled Cooling Fasteners†(2005AA001110).
In 2008, the company also led the National Support Program Project “Development of Low-Cost, High-Strength Non-Quenched and Tempered Cold-Rolled Steel Products for Steel Structure Joints†(2007BAE30B04).
The non-tempered steel series developed by Maanshan Iron & Steel uses micro-alloying, controlled rolling, and cooling to achieve ultra-fine grain structures. This allows skipping the annealing and preparation steps in fastener manufacturing, ensuring performance meets current standards (GB/T 3098.22-2009). This new production route for 8.8–10.9 grade fasteners saves energy, reduces costs, minimizes pollution, and avoids defects like quenching cracks and surface decarburization.
Alloy cold heading steel
Steels like 10B21, ML40Cr, and SCM435 are used for high-grade fasteners of 8.8–12.9 strength classes. Through strict process control, these materials deliver superior performance and excellent cost-effectiveness, making them ideal for demanding applications.
Floor drain
The floor drain is an important interface connecting the drainage pipe system with the indoor floor. As an important part of the drainage system in the house, it is very important for the odor control in the bathroom. We mainly provide different types of stainless steel floor drains, which are anti-corrosion durable and fast drainage, and also have a fashionable appearance, suitable for various styles of bathrooms.
Floor Drain, Perforated Drain Strainer, Stainless Steel Linear Shower Drain,Square Floor Drain, Shower Floor Drain, Shower Linear Drain,Toilet Floor Trap, Linear Shower Drain With Tile Insert Panel,Kitchen Floor Drain, Linear Shower Drain Grate
Jiangmen MEIAO Kitchen And Bathroom Co., Ltd. , https://www.meiaosink.com