Xingtai Steel developed a new product of Aluminum Killed steel wire rod with high Boron and Titanium and low Carbon successfully for their foreign special customer recently. Its chemical content, surface quality and all mechanical properties meet the requirements of the customer after inspection. It is used to produce grade 4.8 outer hexagon bolt by the customer on trial which has been confirmed with good mechanical properties and cold heading performances. The successful development of this grade is considered as a new variety for their products export and international market expansion.
This new grade with high Boron and Titanium specially required by foreign costumer improved its hardenability, but also existing risk of boron brittleness. There is less referential production experience in China. According to requirements of customer and characteristics of this grade, the technicians not only process a mechanism analysis for materials to clear critical control points in each process but also organize personnel of related departments to make a whole process tracking including smelting, continuous casting, rolling, testing and user practice which has guaranteed one time development success.