【作者】 程立本；

【导师】 王华昌；

【作者基本信息】 武汉理工大学 ， 材料加工工程， 2009， 硕士

【摘要】 本文研究对象是用GCr15钢制造的冷作模具。冷作模具的失效形式主要是表面磨损。要显著提高模具使用寿命,最适用的方法之一就是用TD法对模具表面进行渗钒处理,同时对模具基体淬火,使其达到较高硬度,以支撑其表面VC覆层。由于TD渗钒处理是一种扩散过程,需要在较高的温度(960℃左右)条件下才能得到经济实用的VC覆层,而GCr15钢的淬火加热温度仅为810℃～850℃。由于TD渗钒温度与淬火加热温度间的较大差别,以及模具表面VC覆层在400℃以上很容易被氧化,导致GCr15钢的表面渗钒处理工艺与基体淬火强化工艺很难协调一致。常用的先TD渗钒处理再加热淬火的方法由于VC覆层在淬火加热和冷却时很快被破坏,所以在缺乏真空淬火炉的条件下很难取得实际效果。本文针对上述问题进行研究。研究目标是,在缺乏真空淬火炉的情况下,优化整合GCr15钢制冷作模具的TD渗钒处理工艺与基体淬火工艺,取得经济实用及显著提高模具使用寿命的效果。本文的研究内容主要有:1) GCr15钢的TD渗钒处理;2) GCr15钢的淬火工艺;3) GCr15钢TD渗钒处理工艺与淬火工艺的优化整合;4) GCr15钢的TD渗铬工艺。本文研究结论为:1) 960℃TD渗钒后油淬虽然可以满足扩口模和滚圆模的使用要求,但是得到的基体晶粒较大,脆性大;2) 960℃TD渗钒后随炉冷却至830℃,然后在100℃沸水中淬硬,及时回火,能够得到比较厚的覆层,基体硬度达HRC57以上,晶粒也得到细化,具备较高的工业应用价值;3)使用TD渗铬工艺也可以使模具表面硬度、耐磨性大大提高,也可以应用于GCr15钢制冷作模具的表面强化。本文研究成果已得到工业应用,对淬火加热温度在800℃～850℃的冷作模具钢的表面渗钒及基体淬硬工艺具有普遍意义。更多还原

【Abstract】 The research object of this study is the cold molds made of GCr15 steel. The main failure form of cold molds is surface wear. To significantly improve die life, one of the most appropriate ways is to vanadizing mold surface use TD method, while quench the matrix to achieve a higher hardness, in order to support the VC surface coating. As the TD vanadizing treatment is a diffusion process that requires a higher temperature (around 960℃) to get economical and practical VC coating, while the heating temperature of quenching for GCr15 steel is only 810℃～850℃. As the difference between the temperature of TD vanadizing and quenching heating is very large, and the VC coating can easily be oxidized above 400℃, resulting in the TD vanadizing process of GCr15 steel and the substrate quenching process is difficult to strengthen the coherence. As the VC coating can soon be destroyed during the heating and cooling in the quenching, the common process of TD vanadizing and then quenching method is difficult to achieve practical results without vacuum quenching furnace.In this paper, we study the above issues. The research goal is, in the absence of vacuum quenching furnace case, optimize and integrate the TD vanadizing treatment process and the substrate quenching process of cold work die made of GCr15 steel, achieve economic and practical effect, and significantly increase the mold life.This study mainly are: 1) TD vanadizing processing of GCr15 steel; 2) Quenching processes of GCr15 steel; 3) Optimization and integration between TD vanadizing process and the quenching process of GCr15 steel; 4) TD chromizing process of GCr15 steel.This study concludes that: 1) Oil quenching after TD vanadizing at 960℃can basically meet the requirement of the spheronization die and expansion die, but it will get larger matrix grain and make the matrix brittle; 2) Cooled to 830℃with the furnace after TD vanadizing at 960℃, and then hardened at 100℃boiling water, promptly tempering, can get thick coating, and matrix hardness can reach HRC57,the matrix grain have also been refined, and this method have a high industrial value. 3) The use of chromizing process also allows mold surface getting much harder, and gets the wear resistance increased, it can be applied to surface strengthening of cold-working die made of GCr15 steel.This research fruit has been applied to industrial applications, has universal significance for the surface vanadizing and matrix quench hardening process of cold-working die steel whose quenching heating temperature is 800℃～850℃.更多还原