镍对新型热作模具钢连续冷却转变规律与冲击功的影响  

Effect of Nickel on Continuous Cooling Transition Law and Impact Energy of New Hot Work Die Steel

作　　者：关海龙 岳建博 田家龙 龚伟 姜周华 Guan Hailong;Yue Jianbo;Tian Jialong;Gong Wei;Jiang Zhouhua(Jiangsu Hongsheng Die Steel Material Technology Co.,Ltd.,Jiangyin 214400,China;School of Metallurgy,Northeastern University,Shenyang 110819,China)

机构地区：[1]江苏宏晟模具钢材料科技有限公司,江阴214400 [2]东北大学冶金学院,沈阳110819

出　　处：《特殊钢》2024年第6期108-116,共9页Special Steel

基　　金：辽宁省科技计划联合计划项目基金资助(2023 JH2/101700302)。

摘　　要：使用热膨胀相变仪和冲击试验机测定了含0.8%Ni和不含Ni的新型热作模具钢QDH的连续冷却转变曲线(CCT曲线)和冲击功曲线,并结合组织及硬度分析了Ni元素对QDH钢连续转变规律与冲击功的影响。热膨胀曲线测试结果表明,Ni元素可显著降低QDH钢的临界相变点(A_(c1)、A_(c3)及M_(s)),扩大奥氏体相区,使CCT曲线整体右移,珠光体临界冷速由0.03℃/s降低至0.02℃/s以下,马氏体的临界冷速由0.4℃/s降低至0.2℃/s,提高了钢的淬透性。冲击功曲线测试结果表明,两种实验钢均在350~500℃和550~620℃两个回火温度区间,分别出现第一类回火脆性和第二类回火脆性,其中,含Ni钢在整个回火温度区间内的冲击功均高于不含Ni钢,说明Ni元素提高QDH钢淬透性的同时也可提高其韧性。The continuous cooling transition curve(CCT curve)and impact energy curve of QDH of the new hot work die steel with 0.8%Ni and without Ni were determined by thermal expansion phase change instrument and impact testing machine,and the influence of Ni on the continuous transformation law and impact energy of QDH steel were analyzed by combining the microstructure and hardness.The test results of thermal expansion curve show that Ni element can significantly reduce the critical phase transition point(A_(c1),A_(c3) and M_(s))of QDH steel,expand the austenite phase region,shift the CCT curve to the right as a whole,reduce the critical cooling rate of pearlite from 0.03℃/s to less than 0.02℃/s,and reduce the critical cooling rate of martensitic from 0.4℃/s to 0.2℃/s,which improves the hardenability of steel.The test results of impact energy curves show that the first type of tempering brittleness and the second type of tempering brittleness of the two experimental steels are in the tempering temperature range of 350℃-500℃and 550℃-620℃,respectively,and the impact energy of Ni-containing steel in the whole tempering temperature range is higher than that of Ni-free steel,indicating that Ni element can improve the hardenability of QDH steel and improve its toughness.

关 键 词：镍 热作模具钢 CCT曲线 淬透性 冲击吸收功 

分 类 号：TG156.1[金属学及工艺—热处理]