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Dongguan Goodjob Precision Components Co.,Ltd.

ADD: No.68, Changsheng North Road, Dalang,Dongguan,Guangdong,China

Tel: +86-769-23327726

Fax: +86-769-23327736


21.Q: What is carbonitriding?

A: Gas carbonitriding is similar to carburizing, except that small additions of nitrogen are added to the atmosphere and the temperature is slightly lower. Consequently, the case depth and therefore, the load carrying capability is not as high as with carburizing, but the wear resistance and dimensional control are often superior. Carbonitriding has the further advantage that it can be performed on unalloyed steels, so that it can be used for small stampings or other types of machined parts to make a strong, wear resistant part economically.

22. Q: What is Nitriding?

A: Gas nitriding is a surface hardening process, where nitrogen is added to the surface of steel parts using dissociated ammonia as the source. Gas nitriding develops a very hard case in a component at relatively low temperature, without the need for quenching.


23.Q: What is nitrocarburizing?

A: Nitrocarburizing is a variation of the nitriding process. It is a thermochemical diffusion process where nitrogen, carbon, and to a very small degree, oxygen atoms diffuse into the surface of the steel part, forming a compound layer at the surface, and a diffusion layer. Nitrocarburizing is a shallow case variation of the nitriding process.


24.Q: What advantages does nitrocarburizing have?

A:The advantage of the process include the ability to harden materials which are not prehardened, the relatively low temperature of the process which minimizes distortion, and relative low cost in comparison to carburizing or other case hardening processes. This process is done mainly to provide an anti-wear resistance on surface layer and to improve fatigue resistance. Additional advantage is that nitrocarburizing can be applied to the same materials as is nitriding, as well as unalloyed materials, where good wear resistance and some improved fatigue resistance are needed a low cost. It is widely used for stampings, as an alternative to hard plating or even carbonitriding.


25.Q: What is electrophoresis?

A: Electrophoresis is the motion of dispersed particles relative to a fluid under the influence of a spatially uniform electric field. The technique applies a negative charge so proteins move towards a positive charge. It is ultimately caused by the presence of a charged interface between the particle surface and the surrounding fluid.


26. Q: What is zinc phosphating in surface treatment?

A:Zinc phosphating is used to coat ferrous metals to provide rust-proofing and, when applied in conjunction with sealers, superior corrosion protection.  Zinc phosphate is a lighter coating than manganese phosphate and is used as an alternative coating for high wear parts.  Phosphate coatings are porous, making them ideal for surface preparation for additional coatings and painting. The zinc phosphate coating protects the underlying part surface from wear, corrosion, and rust.


27. Q: What is Passivation?

A:The passivate process is designed to remove foreign metals and oils (usually from machining) from the surface of stainless steel. The end finish will not change the dimension of the part nor the overall appearance of the base metal. Passivation purifies the surface of a machined part and therefore improves corrosion resistance.

28: Q: What is electropolishing?

A: Electropolish is a type of finish that smoothens, polishes, deburrs, and cleans stainless steels. The first advantage to this finish that you will notice is that unlike regular polishing methods you will not have any grain lines or left over materials such as polishing rouge.


29: Q: What is the difference between electropolishing and mechanical polishing?

A: Electropolishing is an electrochemical process while mechanical polishing is a mechanical process. Electropolishing is a surface treatment that can improve surface finish as it dissolves material from the surface.Mechanical polishing, like machining, alters a surface by cutting material away from the surface. Electropolishing can improve a surface finish on a microscopic level while mechanical polishing can improve a surface finish on a macroscopic level.


30.Q: What is black zinc plating?

A: Black zinc plating is used to provide corrosion protection and anti-galling properties to parts in high wear, high temperature, and corrosive environments.  It is achieved by applying zinc plating followed by black chromate conversion plating. The result is a uniform, durable coating providing corrosion and wear resistance as well as anti-galling properties. The surface color can range from matte to different iridescent hues. Black zinc plating is thicker than other plating methods, which may affect the dimensions of tight fitting parts.