Sodium dichromate as passivation

[jetson]

We are doing brass plating process.

 

After brass plating - > water rinse -> passivation(Sodium dichromate) for 15-30s -> water rinse -> drying -> baking

 

pH:Sodiumdichromate3.5 (1% solution) 4.0 (10% solution)

 

Since pH is acidic, we worry the hydrogen embrittlement will cause our component crack.

 

[John Cuthber]

A couple of points. First hydrogen atoms cause hydrogen embritlement, not hydrogen ions.

Second, according to Wiki

" These tests have shown that austenitic stainless steels, aluminum (including alloys), copper (including alloys, e.g. beryllium copper) are not susceptible to hydrogen embrittlement "

 

From

http://en.wikipedia.org/wiki/Hydrogen_embrittlement

so brass should be relatively safe.

What are you plating, and what with?

[jetson]

A couple of points. First hydrogen atoms cause hydrogen embritlement, not hydrogen ions.

Second, according to Wiki

" These tests have shown that austenitic stainless steels, aluminum (including alloys), copper (including alloys, e.g. beryllium copper) are not susceptible to hydrogen embrittlement "

 

From

http://en.wikipedia....n_embrittlement

so brass should be relatively safe.

What are you plating, and what with?

 

 

We using SAE1050 steel to do plating with brass. As i know acid pickling then electroplating may cause hydrogen embrittlement.

 

Brass salt

Water rinse 2x

Passivation ( Sodium Dichromate )

Water rinse 2x

Dry

Oven Baking

 

So what is your opinion about the process above ? Thanks for your info.