论文部分内容阅读
内燃机车用铝合金作柴油机活塞时,其性能和使用寿命均难满足要求,为此,我们试验以球墨铸铁作柴油机活塞材料。 1.球铁活塞的技术要求 (1) 球铁的化学成分(%)3.4～3.9C、2.0～3.0Si、0.4～0.8Mn、≤0.1 P、≤0.03 S、0.4～1.0Ni、0.02～0.05Re、0.03～0.06Mg。 (2) 机械性能σ_b≥60kgf/mm~2、σ_(0.2)≥42kgf/mm~2、δ_5≥2%、HB229～302 (3) 金相组织参照“稀土镁球铁金相标准”(JB1802-76),石墨球化率应为1～2级,均匀分布。基体组织铁素体≤30%,其余为细片状或细粒状珠光体或索氏体,不得
Diesel locomotive diesel engine piston, its performance and service life are difficult to meet the requirements, therefore, we test the ductile iron for diesel engine piston material. 1. Ductile Iron Piston Technical Requirements (1) The chemical composition of ductile iron (%) 3.4 ~ 3.9C, 2.0 ~ 3.0Si, 0.4 ~ 0.8Mn, ≤ 0.1P, ≤ 0.03S, 0.4 ~ 1.0Ni, 0.02 ~ 0.05 Re, 0.03 ~ 0.06Mg. (2) Mechanical properties σ_b ≥60kgf / mm ~ 2, σ_ (0.2) ≥42kgf / mm ~ 2, δ_5≥2%, HB229 ~ 302 (3) Metallography Refer to " (JB1802-76), graphite nodular rate should be 1 to 2, evenly distributed. Matrix ferrite ≤ 30%, the rest of the fine flake or fine pearlite or sorbite, shall not