how to avoid rust while heat treating carbon steel 1075
how to avoid rust while heat treating carbon steel 1075
(OP)
we heat the parts, size of 5 cent coin, material 1075, to 1600 F and then quench at polymer water. then temper at 400 F. we always get some of parts, less than 5%, with rust stain. does anyone know how to avoid this.
by the way, we can not get required hardness if quenched in oil.
thanks,
yush
by the way, we can not get required hardness if quenched in oil.
thanks,
yush





RE: how to avoid rust while heat treating carbon steel 1075
De-ionized water should be used for initial & make-up water to minimize salt buildup.
Polymers degrade from both thermal exposure & bacteria. Bacteria can also degrade/eat corrosion inhibitor. Degradation products are often acidic.
Remedies: Use DI water, biocide, corrosion inhibitor, check pH & conductivity (~measures salt), filter (catches some yeast-type fungi). Seek help from the polymer vendor.
RE: how to avoid rust while heat treating carbon steel 1075
RE: how to avoid rust while heat treating carbon steel 1075
the wash process after oil quench left stain (not rust), probably from the soap used in wash tank, on the parts. and customer does not like it. the polymer gives gook looking to parts, but unfortunately some parts get rust. tomorrow i will do a ph test to the polymer according to kenvalach.
thanks,
RE: how to avoid rust while heat treating carbon steel 1075
Of course, depending on your hardness requirements, why not consider a microalloy with forced air cooling from austenitizing temp!
RE: how to avoid rust while heat treating carbon steel 1075
RE: how to avoid rust while heat treating carbon steel 1075
we use city water without di-ionize. the polymer ph is 8, and the quench solution is 9. is that a problem. what is the right ph i should maintain?
yush
RE: how to avoid rust while heat treating carbon steel 1075
That seems fairly normal, but really it depends on the polymer mfr.'s instructions for solution make-up & maintainance. You should already have this info and a vendor contact (maybe pennypinching management stuck you with some generic solution?). Some mfr. websites, alphabetically:
D. A. Stuart Company
4580 Weaver Parkway, Warrenville, IL 60555 USA
www.dastuart.com
Dow Chemical Company
2301 Brazosport Blvd., Freeport, TX 77541 USA
www.dow.com/polyglycols/ucon
Heatbath®/Park Metallurgical
8074 Military Avenue, Detroit, MI 48204
http://www.heatbath.com/park/products
Henkel [presumably they have quenchants]
ht
Houghton International Inc.
Madison and Van Buren Avenues, P.O. Box 930, Valley Forge, PA 19482-0930 USA
www.houghtonintl.com