Modern Surface TreatmentsPlasma (ion) Nitriding
As an alternative to gas nitriding, nitriding plasma (ion) nitriding process has been developed to overcome the shortcomings of the earlier traditional uncontrolled gas nitriding processes and to offer certain operational advantages that gas nitriding does not have. Plasma is essentially a gas nitriding treatment in which the method of delivering nitrogen atoms to the surface of nitrided components is quite different from the standard gas nitriding processes. It occurs at a very low pressure and under high voltage. From the metallurgical, tribological and mechanical properties standpoint the properties of nitrided case obtained with Nitreg® and well controlled plasma technology are comparable. Plasma offers certain distinct advantages such as:- The ease of masking the component surface where nitriding is to be avoided
- Ability to nitride low density powder metallurgy parts
Modern Surface TreatmentsCarbonitriding
It is a thermal process of simultaneously diffusing both carbon and nitrogen into ferrous alloys under partial pressure. This leads to an extremely hard and wear resistant surface. Vacuum carbonitriding is a significant improvement over conventional gas carbonitriding. The process contains all of the inherent benefits of vacuum carburizing, but also has the additional benefit of precise computer control of surface ammonia content. Furthermore, this process does not require any additional refractory burnouts so not only is the end product of higher quality, but it is often less expensive than with competing conventional gas processes.Not sure which process or service is right for you? Contact our global team of heat treat experts and let them guide you or fill out the contact form to put you in touch with one of our experts!
Modern Surface TreatmentsLow Pressure Carburizing
Low-pressure vacuum carburizing is a state-of-the-art thermal process where carburizing is effected under very low pressures (7-13 mbar). Parts are first heated in vacuum to above the transformation temperature of the alloy and then exposed to carbon-carrying gas, or gas mixtures, under partial pressure. Nitrex has developed a revolutionary process called “Pulse-Pressure”, a method quickly becoming the industry standard. Relative to conventional carburizing, the main advantages of the method are:- Shorter cycle time with tight process control
- Repeatable results to within ±0.001″ (±25µm)
- Uniform homogeneity of carburizing case depths
- Significantly reduced size changes and distortion
- Improved fatigue strength
- Better control of the surface layer chemistry
- Eliminates intergranular oxidation
- Environmentally friendly process
Conventional Heat TreatmentsConventional Carburizing
Carburizing is a process of controlled diffusion of carbon into the surface of a component, followed by quenching and tempering, with the objective of increasing the component’s surface hardness. The process is generally applicable to low carbon steels. When conducted in a “conventional”, rather than in a vacuum furnace, we can refer to the process as conventional carburizing. In this thermal process ferrous alloys are heated to above their transformation temperature and exposed to carbon rich medium. Processing temperatures fall in the 1450°F – 1900°F (790°C – 1040°C) range. The diffusion of carbon into the part and the subsequent quench leads to a part with a hard, wear resistant surface and a tough shock resistant core. Solid, liquid and gaseous carbon-carrying medium may be employed, however, the first two are rarely used. Nitrex-offered carburizing is conducted in computer controlled integral quench and pit gas carburizing furnaces. A full range of case depths if feasible with an economically derived limit of approximately 0.250″ (6.4 mm). In addition, Nitrex is capable of selective carburizing where only specific areas of the part are to be treated. Carburizing benefits include:- case depths up to 0.250″ (6.4 mm) are achievable,
- ability to use inexpensive steels and still produce components with hard surface properties,
- generally used for parts subjected to cyclical loading
- cost effective for parts where some distortion is acceptable
Conventional Heat TreatmentsConventional Carbonitriding
Carbonitriding is a process similar to carburizing whereby ammonia is added to the carburizing atmosphere, which results in supplementary nitrogen diffusion into the surface of a treated component.Note: carbonitriding is sometimes confused with nitrocarburizing. Please read the descriptions of both processes to avoid misunderstandings.Not sure which process or service is right for you? Contact our global team of heat treat experts and let them guide you or fill out the contact form to put you in touch with one of our experts!
Conventional Heat TreatmentsConventional Hardening/Quenching
Hardening is one of the oldest metallurgical processes known to man, originally in the form of heating a sword in the fire and then throwing it into the lake to make it harder. The more modern approach is to heat components in an atmosphere furnace followed by quenching, generally in heated oil. The expression “conventional hardening” is used here to differentiate the process from vacuum hardening. It should also be noted that “hardening” is usually referred to as “quenching”. A more refined version of this process is Vacuum Hardening. BENEFITS- Increased strength
- Increased hardness
- Improved fatigue life
- Increased wear resistance
