In the foundry industry, the performance of carburizers directly affects the quality and cost of castings. In recent years, although domestic carburizers have occupied most of the domestic market, for a long time, there has been a certain gap between domestic carburizes and imported products in core performance indicators, which has profoundly affected the production quality and cost control of high-end steel materials in my country.
In comparison, the gap is mainly manifested in three aspects:
First, component purity and impurity control. The fixed carbon content of imported carburizers is usually stable at more than 98%, and the sulfur content is strictly controlled below 0.05%; while the fixed carbon content of domestic products fluctuates greatly, generally between 92%-96%, and the sulfur content is also high, often fluctuating in the range of 0.1%-0.3%. The gap in these basic indicators directly affects the purity of molten steel.
Second, the degree of graphitization and absorption rate. Due to its highly graphitized structure, imported carburizers melt quickly in molten steel, and the absorption rate can reach more than 90%; while domestic products generally have an insufficient degree of graphitization, and the absorption rate mostly hovers around 80%. This efficiency difference forces domestic steel mills to increase the amount of single addition, which not only increases costs but also aggravates the temperature drop and composition fluctuations during the smelting process.
Finally, the product stability is insufficient. The quality of imported products is stable between batches, while the composition and particle size distribution of domestic products are obviously different between batches due to the complex raw material sources and limited process control accuracy, which brings challenges to accurate batching and affects the uniformity of the final steel performance.
To effectively narrow the gap and promote domestic recarburizers to move towards high-end, it is urgent to take systematic improvement measures:
Strictly control the raw material gate: establish a stable supply channel for high-quality low-sulfur petroleum coke or natural graphite, and improve the quality starting point from the source.
Process upgrade: focus on breaking through the bottleneck of high-temperature graphitization technology, optimize the calcination curve, promote efficient desulfurization technology, and improve product purity and graphitization degree.
Standard guidance and quality control strengthening: formulate and implement enterprise or group standards that are stricter than national standards and benchmark international advanced levels, especially strictly controlling the lower limit of sulfur content and increasing fixed carbon requirements; at the same time, introduce a full-process automated quality monitoring system.
Deep integration of industry, academia, and research: In collaboration with universities and research institutes, we will tackle key issues in cutting-edge directions such as special graphite recarburizers and nanocomposite recarburizers, and accelerate the transformation and implementation of technological achievements.
Although the recarburizer is small, it carries the heavy expectations of a strong steel country. Only by facing the gap and working together on raw materials, processes, standards, and innovation chains can domestic recarburizers truly break through bottlenecks and provide strong support for the independent control of my country's high-end steel materials.
