不同温度真空热处理对FeCrMoCBY非晶合金涂层组织结构与摩擦学性能的影响研究

Effect of vacuum heat treatment on microstructure and tribological properties of FeCrMoCby amorphous alloy coatings at different temperatures

摘要:

深部地质钻探过程中，复杂的井下工况对钻具的钻探性能以及可靠性提出了苛刻的要求。钻具钢体表面涂覆具有耐磨耐蚀性的非晶涂层可以有效提高其服役寿命。其中Fe基非晶合金涂层因其优异的耐腐蚀抗磨损性能、较强的非晶形成能力等优势，具有重要的应用价值和较好的经济效益。本文通过大气等离子喷涂技术（Air Plasma Spray， APS）在35CrMo基体上制备得到成分为Fe₄₈Cr₁₅Mo₁₄C₁₅B₆Y₂ （at.%）的非晶合金涂层，并对其进行不同温度的真空热处理，探究了不同温度热处理对涂层基本性能和磨损失效机制的影响。结果表明：涂层经过真空热处理之后，生成的大量硬质相和成分均匀化使得涂层抗磨损性能提高；且随着热处理温度的提高，涂层磨损率逐渐减小。与未经热处理和750 ℃热处理的涂层相比，经过850 ℃热处理之后的涂层具有最佳的抗磨损性能，磨损率仅为未经热处理的Fe基非晶涂层的16.7%。热处理前后涂层的失效机制均为粘着磨损、磨粒磨损、疲劳磨损和氧化磨损。

关键词:大气等离子喷涂;Fe基非晶涂层;真空热处理;摩擦磨损

Abstract:

In deep geological drilling， complex downhole conditions raises demanding requirements on drilling performance and reliability of drilling tools. Wear-resistant and corrosion-resistant amorphous coating on the surface of drilling tool steel can effectively improve its service life. Among them， Fe based amorphous alloy coating has important application value and good economic benefits because of its excellent corrosion resistance and wear resistance， strong amorphous formation ability and other advantages. An amorphous alloy coating composed of Fe₄₈Cr₁₅Mo₁₄C₁₅B₆Y₂ （at.%） was prepared on the 35CrMo substrate by air plasma spraying （APS） technology， and subjected to vacuum heat treatment at different temperatures. The effects of heat treatment at different temperatures on the basic properties and wear failure mechanism of the coatings were investigated. The results showed that vacuum heat treatment produced a large amount of hard phase and homogenized the composition； thus， improving the wear resistance of the coating. With the increase of heat treatment temperature， the coating wear rate decreases gradually. Compared with the coating either without heat treatment or with 750℃ heat treatment， the coating with heat treatment at 850℃ had the best wear resistance， and the wear rate was only 16.7% of that of Fe based amorphous coating without heat treatment. Failure mechanisms of the coatings either with or without heat treatment all include adhesion wear， abrasive wear， fatigue wear and oxidation wear.

Key words:air plasma spraying;Fe based amorphous coating;vacuum heat treatment;friction and wear