diffusion metal carbide coating technology introduction

1. technology introduction
Diffusion method of metal carbide coating technology is the workpiece is placed in the special medium, by diffusion to the surface to form a layer of a metal carbide layer microns to tens of microns. The carbide layer has high hardness, HV up to 1600 "3000 (determined by carbide species), in addition, the carbide coatings metallurgically bonded to the substrate with, does not affect the work piece surface finish, high abrasion resistance, anti seizure (bond), corrosion resistance, can greatly improve the tooling and machinery parts using life.

2.and related technology
Through the method of super hard compound film formed on the surface of the workpiece, is greatly improved the wear resistance, anti bite (anti bonding), corrosion resistance, and thus greatly improve the service life of the effective and economic method. At present, the workpiece surface hardening treatment methods mainly include physical vapor deposition (PVD), chemical vapor deposition (CVD), physical and chemical vapor deposition (PCVD), diffusion method of metal carbide coating technology, in which, the PVD method has low deposition temperature, the deformation of the workpiece is low, but because of poor coating binding force and the base circle plating, process is not good, often difficult to play super hard compound film. The CVD method has good adhesion, craft circle plating to highlight the advantages of good, but for a large amount of steel materials, the matrix hardening treatment is difficult, somewhat careless, film can easily destroy. So its application is mainly concentrated in the hard alloy material. PCVD low deposition temperature, film substrate adhesion and process circle plating than PVD method has greatly improved, but compared with diffusion method, binding force is still a big gap, because PCVD method is still the plasma membrane, although around plating than PVD method has been improved, but cannot eliminate.
The diffusion of metal carbide coating method of metal carbide coating technology was formed, the metallurgical bonding with the substrate, the film substrate is unable to compare with PVD, PCVD together, so this technique can really play a performance advantage, super hard layer in addition, the technology does not exist around the plating issues, subsequent matrix hardening treatment is convenient, and can be repeated many times, the applicability of this technique is more extensive.

3. technological advantages
Diffusion method of metal carbide coating technology widely in Japan, Europe, Australia, South Korea and other countries the application. According to the survey, many imported equipment supporting the mold on the massive use of this technology, the mold in domestic production, due to the lack of corresponding mature technology, tends to make the die life is low, some can't even localization.
The technology of domestic seventy's was studied, but due to various constraints, technology and equipment are often difficult to batch and long-term production test, so that some of the technology in practical problems is not easy to expose or difficult to solve, often give up halfway. We are in the process of research and application of 10 years of in the process, equipment, the practical problems of the existing in the research, and the effective improvement, the improved technology and complete sets of equipment have been able to meet the long-term stable production requirements, service life of the die level reaches the same level of mold processing life, yielded a wealth of practical application experience in the production of various types of mold, has laid a solid technical foundation for large-scale popularization and application of the technology.

4.applicable scope
Diffusion of metal carbide coating technology can be widely applied to various due to wear, occlusion caused by failure of the tooling or machinery parts. Among them, because of the abrasion caused the failures (such as stamping, cold heading, powder molding mould) can improve the life several times to several times; due to occlusion caused by product or die injury problems (such as drawing die, flanging die), can be solved fundamentally.
Applicable materials: die steel, structural steel, carbon content of more than 0.3% cast iron, hard alloy.

Processing technology of stainless steel welded pipe two, die surface hardening
    Stainless steel welded pipe is in welded pipe forming machine, made of stainless steel plate after rolling and forming die if road and welded together by the. Due to the high strength stainless steel, and the structure of the face centered cubic lattice, easy to form the work hardening, the welded pipe forming die: a bear greater friction, the mould is easy to wear; on the other hand, stainless steel sheet and the mold surface forms a bond (occlusal), so that the formation of a welded pipe and the mold surface. Therefore, stainless steel mold good must have high abrasion resistance and anti adhesive (occlusal) performance. Our analysis of the inlet pipe mould show that, surface treatment of the dies are used in super hard metal carbide or nitride coating process.
    Stainless steel welded pipe forming mould material is generally made of high carbon high chromium Cr12MoV (or SRD11, D2, DC53) made of. Currently widely used the following process production mold: blanking, rough machining, heat treatment (quenching and high temperature tempering) → finishing, nitriding and product (Note: in order to save costs, general manufacturers now have saved the forging and annealing of two time, fee property procedure).