【作者】 隋鹤龙；

【导师】 姜启川；

【作者基本信息】 吉林大学 ， 材料加工工程， 2006， 博士

【摘要】 本文采用THERMO-CALC软件优化了新型高Cr热作模具钢（HHD钢）的成分设计,并以该成分为依据研究了碳、铬含量,孕育变质和强韧化热处理工艺对HHD钢组织、力学性能、热疲劳性能等的影响规律与作用机制。研究发现,新型HHD钢为低碳板条马氏体钢,具有优良的淬透性,过冷奥氏体十分稳定,在冷却速度小于0.53℃/s时（冷却30分）才有碳化物析出,而H13钢冷却90秒后就开始有碳化物析出。HHD钢经强韧化热处理后,获得了大量弥散分布在基体上的纳米级MC、M₂₃C₆和Mo₂C型碳化物,这些弥散的纳米级碳化物十分稳定,保证了HHD钢的高温弥散强化效果,大大地提高了HHD钢的高温性能。实验结果表明,新型HHD钢的高温强度、抗热疲劳性、耐磨性、抗氧化性、热塑性（锻造成型性）和热稳定性均优于ASSAB8407（进口H13）钢。研究发现热作模具的使用寿命不仅与强韧性有关,同时还与氧化密切相关,氧化大大地加快了热疲劳裂纹的萌生与扩展和高温下的磨损。新型HHD钢具有高的强韧性与抗氧化性的良好配合,使其使用寿命大大高于H13、3Cr2W8V等商业热作模具钢。生产实验表明,采用HHD钢制造的铜合金放气阀本体压铸模具、铜合金汽车变速箱同步环精密锻造模具、汽车输出法兰第三工位冲头热镦模具和空调调节阀锻造模具,使用寿命分别是目前企业正在使用的H13、3Cr2W8V等钢加工而成的同类模具的2.3⁴.8倍、10倍、1.6倍和3倍,而且新型HHD钢模具成本较低,深受应用者欢迎。可见,本研究开发的新型HHD钢具有广阔的应用前景与显著的经济效益!更多还原

【Abstract】 The dies are called as“black gold”because of their high cost and complicated process, and the die fabricating level is an important marking that measures a national product manufacturing level. In recent years, the whole world die steels market total amount is in a motion of 60 ~ 65 billions dollars. In China, die industry was listed as the industry of the point support development policy in the document“The decision of the important point concerning the current industry adjustment policy”promulgated by State Department in 1989, and in the following 10 years the production value of die industry increased near 930%. To 2002, the Chinese production value of die industry was 36 billions RMBs and then increased about 17% every year. With the adjustment of the global economic industrial structure, the center of traditional industry, such as manufacturing, transfers toward developing country because of the gradual saturation of Euro-American market, the raise of labor cost year by year, and the reduce of profits, which brings the unprecedented opportunity to China for the development of die business and decides that China will necessarily become a big country of the die production.With the high-speed development of mechanical industry, more and more parts are processed by hot extrusion and finish forging, so the hot working dies play an increasingly important role in today. Compared with the developed countries, the die industry of our country still relatively falls behind, of which the main representations are having few of the new die materials with independent intellectual property, the out-of-date means of die manufacturing, the low using life of dies, and the low producing efficiency. Therefore, developing the high-quality hot working die steels with complete independent intelligent property, raising the using life of hot更多还原