Paper Machinery

Feature of our production process:
1.Material refining technology,fewer impurities,high purity,largely reducing harmful elements content(such as elements S,P ), thus comprehensive mechanical performance of material is raised.
2.Through roll forging, material is processed and strengthened and material fibre is complete and uniform, which increases integrated mechanical performance of material.
3.FDSP Company has the world advanced forging equipment and technology,electronic data processing systems and perfect quality control system.
4.Ring die blank,generally chromiumalloy roll forgings, some factories use 45 ordinary carbon steel.
5.Hardness of blank must be controlled, ranging from HB170 to HB220.If the hardness is too high,the drill is easy to break and happens with die hole when drilling. If hardness is too low, the surface finish of die hole will be not good.
6.In order to control blank inner material uniformity, every blank must be carried out with fault detection, which can avoid defects such as flaw, pore-free,crackle and inclusions etc.
7.After machining and heat treatment process, hardness of ring die can be up to HRC 52-58(inner diameter less than 350mm),HRC50-56(inner diameter more than 350mm),more wearable and anti-corrosion.
8.In order to control hardness uniformity of ring die after heat treatment, we choose more than three points in each part of trisection of peripheral direction to test hardness and take average.The difference of hardness value between each part should not be higher than HRC4.
9.According to the principle of metal material science combined with gas quenching and C,Cr,Mn,Ni,V elements content is optimized, forming the standard of ring die.




Vacuum heat treatment
1.Suitable hardening temperature of vacuum furnace ensures higher hardness and impact toughness.
2.Suitable drawing temperature ensures no cracks of ring dies and little wear of hole and surface, which improves the working life.
3.In same loading, adding b