and locate the following document
"Practical Guidelines for the Fabrication of Duplex Stainless Steels" from the IMOA (the International Molybdenum Association). It can be downloaded. This is one of the best technical documents that has information regarding fabrication of duplex ss including a blurb on post weld cleaning of heat tint.
NiDI Technical Series 10004 - FABRICATION AND POST-FABRICATION CLEANUP OF STAINLESS STEELS (1986)
By Arthur H. Tuthill, reprinted from Chemical Engineering, Sep 29, 1986. The surface condition of stainless steels is critical where the product must not be contaminated; pharmaceutical, food and nuclear plants and where the stainless must resist an aggressive environment. Embedded iron, grease and heat tint can initiate corrosion unless properly removed or, in some cases, prevented. Provides a guide to solving the problem.
Hill, J.W., Welding Journal, May 2002, pp40-43
Steve Jones
Petroleum Development Oman LLC
Muscat
Sultanate Of Oman