Casting is generally divided into gray cast iron casting and ductile iron casting. Due to the different casting processes, the demand for recarburizers is also different. Generally, the recarburizer for gray casting requires a lower sulfur content, which is normally 0.5 The following sulfur can be used. The requirements are not so strict. Generally, fixed carbon 98.5/98/90/95/92 can be used. Even some manufacturers can use fixed carbon 85 to save costs, as long as the final absorption rate can be used. Just reach it. But for nodular cast iron, the requirements are more stringent. It not only requires a fixed carbon content, but also requires low sulfur and low nitrogen, especially the sulfur content must be low, and only the ones below double zero can be used, otherwise the produced castings It is easy to be brittle and has cracks, which greatly affects the final effect, and there are certain requirements for nitrogen. It must be low nitrogen, preferably 600ppm or less than 300ppm. Some manufacturers even require less than 100ppm. Of course, the lower the nitrogen, the better, because the more nitrogen Castings produced at low levels are smoother and flat, without pores. Higher nitrogen will cause uneven castings, and some even have pores and cracks, so you must be cautious when choosing a recarburizer, and must be based on your own reality. The most important thing is to choose the right product for the situation.
Therefore, for gray cast iron, the required recarburizer does not require so much sulfur, and there is no need for low-sulfur and low-nitrogen recarburizers. Ordinary high-sulfur or medium-sulfur recarburizers can be used completely, so there is no need to waste a lot. Cost, when choosing a recarburizer, it is perfectly fine to choose a petroleum coke recarburizer or a semi-graphitized recarburizer, but you must choose a recarburizer with good quality and high absorption rate to use.