高密度铁基粉末冶金零部件制造原料的研究

Design of high density powder mixtures for warm compaction

温压粉末原料是采用温压成形技术制造高密度粉末冶金零件的基础和温压工艺的技术核心。高价格的进口温压粉末制约了我国高密度铁基粉末冶金零件的开发与应用,因此,必须开发出符合我国国情的温压粉末原料体系。作者根据我国资源特点,采用鞍钢产水雾化铁粉、水雾化低合金钢粉和攀枝花钢铁公司产转炉烟尘铁粉为原料,进行了制备相应体系的温压粉末原料和温压工艺参数优化的研究。以水雾化铁粉为原料设计制造的Fe-1.5Ni-0.5Mo-0.5Cu-0.6C粉末经637MPa压制,温压密度为7.46g/cm^3;压坯的回弹率为0.03％.在1150℃烧结40 min后,收缩率为0.025％。而以转炉烟尘铁粉设计制造的Fe-1.5Ni-0.5Mo-0.5Cu-0.6C粉末经686 MPa压制,压坯密度达7.35g/cm^3;以Fe-1.5Ni-0.5Mo水雾化合金钢粉为原料制造的Fe-1.5Ni-0.5Mo-1.5Cu-0.8C粉末在686 MPa时压制密度为7.35g/cm^3。这些粉末原料的设计为我国高强度铁基粉末冶金零部件的制造创造了条件。

Preparation of high performance powder mixture designed for warm compaction is a key technical step for fabricating higher density ferrous P/M parts in so-called ARCODENSE^(TM) process. The higher prices of powder mixtures for warm pressing restrict the development of our high performance ferrous P/M parts, and lowering cost of such powder mixture is neccessary to develop our own powder metallurgy technology and mobile industry. Considering characteristics in iron powder sources of home country, powder mixtures designed for warm pressing fabricated from water-atomized iron powder, iron particles recycled from rotary furnace in steelmaking and water-atomized steel powder can satisfy such reqirement, and optimization of warm compaction processing Was also investigated. It was shown that, the compact with density up to 7.46 g/cm^3 was reached after pressed at 637 MPa with very small springback of 0.03% and sintering shrinkage of 0.025% from water atomized iron powder, 7.35 g/cm^3 at 686 MPa both from the recycled iron powders and water atomized alloying steel powders. Successful design of these powders is helpful to the development of Chinese high performance ferrous P/M parts.