Embrittlement of steels, can cause brittle fracture under stress, this occurs as a result of the absorption of hydrogen, phosphorus or carbon during cleaning, electroplating phosphate coating and heat treatment processes.
The susceptibility to embrittlement increases with increasing stress and increasing material strength. Therefore, the specification of cleaning and finish requirements for hardened steel parts is crucial in reducing the risk of embrittlement.
Typical electrolytic processes which cause hydrogen embrittlement are: acid zinc, bright cadmium, bright nickel & bright chrome.
De-embrittlement is a heat treatment process which is carried out after electroplating where hydrogen embrittlement is likely to take place.
De-embrittlement after plating is usually done in the region of 200 – 220 centigrade for 120 to 240 minutes.
The heat treatment or de-embrittlement shall commence as soon as possible, preferably within 1 hour but not later than 3 hours after plating has been performed.
Note :
Please consult with your heat treater for availability of furnaces in the size, shape and capacity required to De-embrittle your components.
This should be done days prior to plating being performed to allow sufficient time to organize for the process to be done in the required elapsed time between each process of plating and De-embrittle.
Guidance and information is always available from our experience heat treatment professionals.
Our procedures and work instructions are fully documented under our AS 9100 and ISO 9001 quality management systems.