Black Stainless Steel Revisited
In my December column, I briefly discussed a number of ways for blackening of stainless steel. A reader’s e-mail reminded me that there is a commercial proprietary product available for blackening stainless steel based on copper-selenium chemistry. It is used at room temperature. More information can be obtained by doing an internet search under the term “blackening process.” The original question and answer is reprinted below.
Q: Our company has been asked to bid on a project that involves the blackening of stainless steel. The company does not call out any specifications. We have never performed this metal finishing process. What are some of the methods used for blackening of stainless steel? F. B.
A: I must say I’m a little bit surprised that your potential customer has not specified a process that should be used. That being said here are a few methods that have been used to blacken stainless steel. (see Figure 1) Before you consider this project, it would be a good idea to discuss it in more detail with the company and find out exactly what properties they are looking for in the final finish.