熱處理對20鋼韌脆轉(zhuǎn)變溫度的影響

Effect by Heat Treatment on DBTT of 20 Steel

摘要: 針對煤炭行業(yè)常用的20鋼凍結(jié)管的作業(yè)環(huán)境,參考低溫用管的有關(guān)標(biāo)準(zhǔn),對熱軋態(tài)及不同正火狀態(tài)下的20鋼凍結(jié)管的拉伸性能和低溫沖擊韌性進(jìn)行檢驗(yàn)分析,并采用Origin軟件擬合20鋼的韌脆轉(zhuǎn)變溫度曲線。分析結(jié)果表明:經(jīng)過860℃、880℃、910℃正火后,20鋼的韌脆轉(zhuǎn)變溫度下降到-30~-20℃;正火態(tài)的組織晶粒度比熱軋態(tài)的粗大,但正火后20鋼的低溫沖擊性能大幅度提高。

Abstract: Addressing the operation conditions for the 20 steel freezing pipes as used for coal mining industry, and using applicable standard for cryogenic pipes for reference, the tensile property and low temperature impact toughness of the as-hot rolled pipes and pipes as normalized variably are tested and analyzed, and the Origin software is used to fit the DBTT (ductile brittleness transformation temperature) curve. Result of the analysis reveals that after being normalized at 860 ℃, 880 ℃ and 910 ℃, the DBTT of the 20 steel drops to -30~-20 ℃, and the grain size of the normalized structure is more coarse than that of the as-hot rolled structure, whereas the post-normalization low temperature impact property of the steel is remarkably increased.