YD系列硬质合金高强度钢或超高强度钢的零件。用YT类老牌号硬质合金加工,在粗车、半精车和精车工序中,都存在刀具磨损快、耐用度低及加工效率低等问题。加之,当产品的产量大,毛坯余量大时,不仅要求刀具耐磨而且要有足够的强度。因此,急需研制新型硬质合金,以便提高切削加工水平。针对上述问题,从1975年开始,由国营北方工具 YD series of carbide high strength steel or high strength steel parts. With YT old class cemented carbide processing, in the rough car, semi-fine car and fine car process, there are fast tool wear, low durability and processing efficiency and other issues. In addition, when the product of large output, large stock allowance, not only requires wear-resistant tool but also have sufficient strength. Therefore, the urgent need to develop a new type of cemented carbide, in order to improve the level of cutting. In response to the above problems, from 1975 onwards, by the state-run North Tools