熱處理工藝對700℃以上超超臨界電站用鎳基合金組織及性能的影響
Effect of Heat Treatment on Structure and Properties of Nickel-based Alloy for Ultra-supercritical Unit above 700℃
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摘要: 通過改變固溶熱處理溫度、保溫時間，對一種新型700℃以上超超臨界電站用鎳基合金冷軋后的熱處理工藝進(jìn)行研究，并借助金相顯微鏡、掃描電鏡（SEM）和硬度等表征手段，揭示不同熱處理制度對其組織及性能的影響規(guī)律。結(jié)果表明：隨著固溶溫度升高和保溫時間延長，該新型高溫鎳基合金晶粒逐漸長大，硬度和抗拉強度下降；固溶溫度超過1 100℃時，在晶界和晶粒內(nèi)部均有少量MC等強化相析出；當(dāng)固溶溫度超過1 130℃或保溫時間超過45 min，部分晶粒出現(xiàn)異常長大，組織不均勻性增加，碳化物析出相開始回溶；該新型高溫鎳基合金的最佳固溶熱處理工藝制度為1 100℃保溫30 min。Abstract: By changing the temperatures and holding times of solution treatment，a study is carried out on the heat treatment process for a new-type of nickel-based alloy（as-cold-rolled） for ultra-supercritical unit above 700℃.The law of effects of different heat treatment processes on the structure and properties of the alloy is revealed by means of metallographic microscope and scanning electron microscope（SEM）.The results show that as the temperature and holding time of a solution treatment increases，the grain size of the superalloy increases gradually，and its hardness and tensile strength decreases.When solution treatment temperature exceeds 1 100℃，a few strengthened phases such as MC phase precipitates at the grain boundaries and within the grains.When solution treatment temperature exceeds 1 130 ℃ or holding time exceeds 45 minutes，some grains abnornally grow，the inhomogeneity structure increases，and the carbides start to dissolve again.The optimum solution treatment process for the new-type of nickel-based superalloy will be a treatment temperature of 1 100℃and a holding time of 30 minutes.
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