The main reason for removing hydrogen after plating is to prevent the occurrence of hydrogen embrittlement.
Author: Anna
The main reason for removing hydrogen after plating is to prevent the occurrence of hydrogen embrittlement.
During the plating process, especially surface treatment such as pickling and electroplating, the metal substrate and the plated layer will penetrate hydrogen atoms. These hydrogen atoms will penetrate through the metal crystallization, leading to an increase in the brittleness of the metal, which will trigger the early brittle fracture phenomenon, i.e. hydrogen embrittlement.
Definition and effects of hydrogen embrittlement
Hydrogen embrittlement is the phenomenon of early brittle fracture of a metallic material due to hydrogen penetration. Hydrogen atoms accumulate within the metal, resulting in a decrease in toughness and susceptibility to sudden fracture under stress.14 This phenomenon is particularly evident in high-strength structural steels and elastomeric parts, which are sensitive to hydrogen and susceptible to hydrogen embrittlement.
Methods of hydrogen removal
Hydrogen removal treatment is usually done by heat treatment, in which the plated workpiece is heated and held in a high-temperature oven for a period of time, so that the infiltrated hydrogen atoms can rediffuse back to the surface and be released from the metal.
The specific temperature and time vary according to the material and shape, but the general temperature is 200~250℃ and holding time of 2~4 hours is sufficient.13 For thick plated products or workpieces working under high stress conditions, the holding time may need to be longer, even up to 4~6 hours.