添加合金元素对耐热铸铁显微组织和抗拉强度的影响

摘要

The microstructures of five kinds of ingots with different chemical compositions were ob‐served by optical microscope and the tensile strength of each sample was measured at different tem‐peratures .The effects of carbon and alloying elements on the tensile strength of the samples were in‐vestigated .The results show that the high temperature tensile strength of the samples can be im‐proved by adding appropriate amounts of nickel and molybdenum w hen the carbon content is reasona‐ble .Additionally ,the tensile strength of vermicular graphite cast iron ,which has the composition of 3 .72% C ,2 .45% Si ,0 .661% Mn ,0 .90% Cr ,0 .66% Ni ,0 .12% Mo and 0 .159% Cu ,can still maintain 358 M Pa at 600 ℃ .%利用光学显微镜观察五组不同化学成分铸锭的显微组织，并对铸锭试样在不同温度下抗拉强度进行测定，研究碳元素和合金元素对铸铁抗拉强度的影响。结果表明，在碳含量适宜的情况下，添加适量合金元素Ni、Mo能提高铸铁的高温强度；w（C）为3．72％、w（Si）为2．45％、w（Mn）为0．661％、w（Cr）为0．90％、w（Ni）为0．66％、w（Mo）为0．12％、w（Cu）为0．159％的合金蠕墨铸铁在600℃高温下的抗拉强度仍能达到358 M Pa。