新型合金工具钢软氮化特性的初步探索

【作者】 杨闯；

【导师】 梁益龙；

【作者基本信息】 贵州大学 ， 材料学， 2006， 硕士

【摘要】 本文对一种GDL-4新型合金工具钢的软氮化特性进行了初步的探索。并与传统的高速钢进行比较，对新材料的软氮化工艺、渗层组织与相组成、耐磨性、脆性等方面进行了研究。 研究结果表明，GDL-4钢经过560℃×3h软氮化后渗层显微组织是由γ’和合金氮化物及碳化物组成的扩散层，未见连续的ε相形成，心部组织为碳化物+回火马氏体+残余奥氏体。渗层硬度梯度平缓，表面硬度达HV1100～1400，心部硬度为HV800～900，渗层力学性能优良。与传统高速钢比较，在相同工艺条件下渗速较快，渗层脉状氮化物级别低，脆性小，耐磨性更佳。 新材料中非氮化物形成元素Si与N的亲和力很小，可起到阻碍N原子聚集的作用，从而推动N原子较快的向内扩散，形成较平缓的氮浓度梯度，因而有一定提高渗速的作用。M2钢中在软氮化时大量的强氮化物形成元素与氮形成稳定的氮化物将其固定住，阻抑氮向工件内部扩散。故在相同条件下渗氮，GDL-4钢的渗速较M2钢更快，可获得更深的扩散层。新材料中非氮化物形成元素Si可阻止化合物聚集的作用也可使化合物均匀分布，从而使得新材料中脉状氮化物的级别较低。 非氮化物形成元素Si和弱氮化物形成元素Mn降低了钢渗层的氮碳浓度，形成比M2钢更深的扩散层及理想的渗层组织，渗层硬度梯度平缓，少量的Al在渗层表面形成AlN化合物对提高表面耐磨性有一定作用。实验结果表明，GDL-4钢具有优异的耐磨性。在实际应用中通过经验观察，以M2钢滑块在相互碰撞时更易发生棱边崩脆现象来判定其渗层的脆性，结果表明，新材料脆性更低。更多还原

【Abstract】 Nitrocarburized characteristics of a new kind of GDL-4 alloys tool steel is investigated. The comparison with the traditional high-speed steel, nitrocarburized technics, microstructure of nitrocarburized layer, phase form, wear resistance, brittleness and so on of the new material was studied in this article.Investigated result show that the microstructure nitrocarburized layer of GDL-4 steel mainly consist of γ ’ phase and alloy nitrocarburizes in the transition layer, continuous ε phase was not formed, the inner microstructure is carbides, temper martensite and remain austenitic after 560 ℃ × 3h nitrocarburized technics, the rigidity grads of nitrocarburized layer is flat, the surface hardness and core hardness of the alloys tool steel are HV1200-1400 and HV800-900 respectively, mechanical properties of nitrocarburized layer is excellent. In the same technological condition, the new alloys tool steel has more faster nitrocarburized speed, more lower brittleness and better wear resistance, the nervation nitride has more lower level in nitrocarburized layer than traditional high-speed tool steel.Non-nitride formed element silicon and nitrogen’ s small appetency may prevent nitrogen get together, which drives the nitrogen atom to enter into to the inner direction, forms the gentler nitrogen gradient concentration, this action may improve nitrocarbrized speed. The massive strong nitrides formed element of M2 steel and nitrogen become steady nitrides, nitrogen was fixed up, this effect may prevent nitrogen to come into the inner. In the same technological condition, the GDL-4 steel can get more deep transition layer. Silicon in the new material has the action that prevent nitride to get together may compound distribute symmetrically, so that the nervation nitride has lower level in nitrocarburized layer than M2 steel.Non-nitride formed element silicon and Weak nitride formed element manganese may reduce concentration of nitrogen and carbon, and GDL-4 steel has more rational microstructure in nitrocarburized layer and more deep transition layer than M2 steel, the result is that the GDL-4 steel has more flatter rigidity grads. A few A1N compound may improve wear resistance in the new material. Experiment effect prove that GDL-4 steel has better wear resistance. Experience observation show that slip-piece of M2 steel is easier fragile in the interactional collision, therefore the GDL-4 has more lower brittleness.更多还原