Preliminary Exploration Of The Characteristics Of The New Soft-nitride Alloy Tool Steel

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.