【正文】 面的空氣轉(zhuǎn)換慢得多比淬火，大截面預(yù)硬塑料模具鋼很難獲得馬氏體在整個(gè)截面中。預(yù)硬鋼的淬透性在本文中被稱為貝氏體淬透性。由于這一點(diǎn)，碳含量必須在 %到 %之間。特別是“ ”設(shè)計(jì)在低碳素鋼中可以得到充分的貝氏體結(jié)構(gòu)在一個(gè)很大的冷卻速度范圍內(nèi) [8]。錳，鉻也可以增加來(lái)增加淬透性，因?yàn)樗鼈兛梢蕴峁┳罡叩?BS溫度和最低的 MS溫度，它們具有良好的焊接性。 3 工廠試制預(yù)硬鋼 根據(jù) 8號(hào)鋼，預(yù)硬鋼鍛造后尺寸為 460毫米 800毫米 3200毫米。貝氏體的顯微結(jié)構(gòu)無(wú)論是在核心和表面上看，并沒有出現(xiàn)大規(guī)模的鐵氧體，如圖 3所示。 具有良好的貝氏體淬透性鋼從實(shí)驗(yàn)室中的 9號(hào)試驗(yàn)鋼中選擇，它的化學(xué)成分是。 預(yù)硬鋼成功的生產(chǎn)在工廠是根據(jù)實(shí)驗(yàn)室里產(chǎn)生的 8號(hào)鋼為基礎(chǔ)的。 參考文獻(xiàn) ： [1] CHEN Zaizhi,MA Mould Steel Application Manual[M]. Beijing:The Chemistry Industry Press,2021(in Chinese) [2] LUO Yi , WU Xiaochun. Research Progress of the Work on Prehardened Plastic Mould Steel[J].Heat Treatment of Metals,2021,32(12):22(in Chinese) . [3] SONG Dongli,GU Jianfeng,ZHANG Weimin, Simulation on Temperature and Microst ructure DuringQuenching Process for LargeSized AISI P20 Steel Blocks Used as Plastic Die[J ].Transactions of Materials and Heat Treatment,2021,25(5):740. [4] WU Xiaochun , ZHANGJie , CUI Kun. The Microst ructure and Mechanical Properties of Unquenched and Untempered Die Steel for Plastic Mould [J ]. Journal of Huazhong University of Science and Technology ,1995 ,23(12): 1(in Chinese) [5] JIANG Laizhu , of a NonQuenched NonTempered Bainitic Steel for Plastic Mould :Continuous Cooling Transformation Behavior[A].J eglit sch F,Ebner R,Leitner H , of the 5th International Conference on Tooling[C].Leoben:. [6] SONG Dongli,GU Jianfeng,PAN Jiansheng, of Quenching Process for LargeSized AISI P20 Steel Block Used as Plastic Die[J].Journal of Materials Science and Technology,2021,22(1):139. [7] LIU Zhuang,WU Zhaoji,WU Jingzhi, Simulation of Heat Treatment[M].Beijing:Science Press,1996(in Chinese). [8] Pickering F B. Physical Metallurgy and the Design of Steels[M].London: Applied Science Publishers LTD,1978. [9] Vetter P,Hippenstiel New PreHardened Plastic Mould Steel as a Tailored Solution for Large Moulds[A].Rosso M,Actis Grande M,Ugues D,eds. Proceedings of the 7th International Conference on Tooling[ C].Torino: . 附件 2：外文原文 （復(fù)印件） Development of NonQuenched Prehardened Steel for Large Section Plastic Mould LUO Yi , WU Xiaochun ,MIN Yongan , ZHU Zhu , WAN G Hongbin (School of Materrial Science and Engineering,Shanghai University,Shanghai 202172,China) Abstract： In order to meet the demand of prehardened steel for lar ge section plast ic mould and save energy,a non –quenched prehardenedNQP steel is decelop. The temperature field of a large block is researched by finite element method simulation and 9 test steels are designed in the microstructures and hardness are investigated when they are air cooled and control cooled at cooling rate similar to the result shows that the hardness uniformity through section is closely correlated to bainitic hardenability for the NQP steel,and the hardness of steel() fluctuates between HRC 40 and 43 under both cooling test steel has better machinability pared with C45 steel,and the NQP steel is produced successfully in the factory based on the laboratory microstructure is bainite,and it is distrebuted uniformly through the size of 460 mm 800 mm 3200 mm. Key words : NQP steel 。 temperature lestimation 。 microstructure 。 1 mm/ r and the cutting depth was changed from mm to mm every mm , the main cutting force was measured by a piezoelectric force dynamometer at the cutting speed of 39 m/ min and m/ min , flank wear of tool was measured using a tool maker′ s microscope with precision of mm. When the feed rate and the cutting depth were fixed at ,