I recently found a brand new factory built aster Stirling that sells for $2000,this little jewish has never been steamed ,so I purchased it. But when I took it to my home,opened the steam chest, I found that the stainless steel fastening screw of one of the slide valves had severely rusted with half of it turning into mud, so I can’t remove it easily ,which made me curious about how this happened and why stainless steel also rusted like this.