蠕墨铸铁CA6110柴油机缸体的试验研究

Experimental Study on Compacted Graphite Iron CA6110 Diesel Engine Cylinder Block

在现有汽缸体高压造型生产线上进行大马力柴油机蠕墨铸铁缸体的试验，试验铁液化学成分w为3．6％～3．9％C；2．2％～2．4％Si；0．2％～0．5％Mn；P≤0．06％；S≤0．03％，采用自行研制的成分为8％～10％Mg。2％～3％RE的蠕化剂进行冲入法蠕化处理，同时加入0．8％～1．0％Cu和0．03％～0．05％Sn，成功的铸造出蠕墨铸铁CA6110柴油机缸体。对附铸试样和铸件本体进行了金相组织和力学性能检测，结果表明，试样的的蠕化率可达80％～85％，珠光体含量达80％～85％，力学性能σb〉480 MPa，δ=1．0％～1．5％，180～200HBS；缸体铸件本体的蠕化率同样为80％～85％，硬度可达197～214HBS。试验结果表明：采用的铸造工艺方案是合理的，在铁液中加入的Cu和Sn可明显增加蠕墨铸铁的珠光体数量，提高抗拉强度和硬度，满足大马力柴油机对性能的要求。

Experimental study on casting technology of compacted graphite iron powerful diesel engine cylinder block was carried out on existing cylinder block high pressure molding line. The composition of base iron was 3. 6% ～3. 9% C; 2.2%～2.4% Si; 0. 2% ～0. 5% Mn; P≤0.06%; S≤0.03%. The base metal was treated by self-made alloy containing 8% ～10% Mg and 2% ～3% RE, with addition of 0.8 % ～ 1.0 % Cu and 0.03 % ～ 0.05 % Sn. Microstructure was examined and mechanical property was tested on samples taken from cast-on block and the cylinder block body. Results indicated that addition of 0.8% ～ 1.0% Cu and 0.03% ～0.05% Sn increases pearlite content, strength and hardness significantly. For the cast-on samples microstructure with 80～85 % vermicular graphite and 80～85% pearlite, tensile strength σb〉480 MPa, δ=1.0% ～1.5%, hardness 180～200 HB were obtained. For cylinder block body 80～85% vermicular graphite, 80～ 85% pearlite and hardness 197～214 HB were also achieved. The results show that compacted graphite iron CA6110 diesel engine cylinder blocks can be manufactured with the experimental technology and meet the property requirement of powerful diesel engine cylinder block.