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摘要: 本文主要研究了蠕墨鑄鐵的組織形態(tài)以及力學(xué)性能，對比了在不同蠕化率下的蠕墨鑄鐵的力學(xué)性能以及顯微組織，得出了蠕墨鑄鐵的性能以及蠕化率的關(guān)系。同時研究了不同蠕化率的蠕墨鑄鐵的滾動磨損性能，通過對比蠕墨鑄鐵、灰鑄鐵和球鐵的滾動磨損亞表面的石墨形態(tài)，得出石墨形態(tài)和滾動磨損之間的關(guān)系。最后分析了滾動磨損的磨屑，了解了整個的磨損過程。通過試驗(yàn)，得出以下結(jié)論：

（1）蠕墨鑄鐵的蠕化率越低，它的力學(xué)性能越好，抗拉強(qiáng)度越高，硬度越高。蠕墨鑄鐵的機(jī)械性能接近于球墨鑄鐵，同時還有良好的鑄造性能、切削加工性能和相當(dāng)高的導(dǎo)熱性能。因此，蠕墨鑄鐵具有良好的綜合性能。鑄鐵中石墨形態(tài)和基體組織是決定鑄鐵性能的最主要的因素。一般情況下，蠕化率越高，基體組織中的鐵素體的含量越高，抗拉強(qiáng)度越低，導(dǎo)熱性能越好。

（2）不同蠕化率的蠕墨鑄鐵滾動磨損性能不同。載荷一定時，蠕化率越低，表面越不容易產(chǎn)生裂紋，則滾動磨損性能越好。蠕化率一定時，載荷愈大，表面產(chǎn)生的裂紋就愈多。

（3）經(jīng)過滾動磨損之后，蠕墨鑄鐵和灰鑄鐵中的石墨變得聚集起來，同時石墨變粗。石墨越多，越粗大，分布越不均勻，則力學(xué)性能越差。

關(guān)鍵詞：蠕墨鑄鐵  蠕化率  磨損  滾動磨損 石墨形態(tài)

 

 

ABSTRACT: This paper studies the compacted graphite cast iron structure and mechanical properties compared in different percentage of vermicular graphite compacted graphite cast iron under the mechanical properties and microstructure properties of compacted graphite cast iron is obtained and the relationship of creep rate. While different rate of compacted vermicular graphite cast iron of rolling wear properties, by comparing the vermicular graphite cast iron, grey cast iron and nodular cast iron wear surface of graphite morphology, come to the relationship between the graphite morphology and wear. Final analysis of the wear debris, understanding of the wear process. Through the test, reached the following conclusions:

( 1 ) Lower rate of compacted graphite cast iron, its good mechanical properties, high tensile strength, high hardness. Mechanical properties of compacted graphite cast iron close to nodular cast iron, as well as good casting performance, cutting performance and very high thermal conductivity , therefore, vermicular graphite cast iron with good performance. Cast iron graphite morphology and performance of cast iron matrix structure was decided the most important factor. Under normal circumstances, rate to creep higher, matrix of ferrite content in high tensile strength , the lower the heat conductivity, the better.

( 2 ) The different rate of compacted vermicular graphite cast iron roll and wear properties are different. When the load is constant, creeping lower, less prone to cracks on the surface, rolling wear properties as possible. When the rate of creep, loads more, more surface cracks.

( 3 ) After passing through the rolling wear, vermicular graphite cast iron and grey cast iron together, while graphite thicker. Graphite, the more, the more coarse and less evenly distributed, worse mechanical properties.

Key words:  vermicular graphite cast iron；creep rates；abrasion；rolling wear；graphite morphology