Novel Approach for Welding Stainless Steel Using Cr-Free Welding Consumables
Abstract
This project was a SERDP seed grant that was extended from the normal one year duration to a total of two years. The goal of the project was to demonstrate the feasibility of a new approach for welding stainless steel using Cr-free consumables. Stainless steels are usually selected as a material of construction for their corrosion resistance. When they are fabricated into structures, stainless steel components are often joined by welding. In order to ensure that the welds exhibit sufficient corrosion resistance, filler metals matching or exceeding the chromium (Cr) content of the base metal must be used. The Cr content of Types 304 and 308 stainless steels, the most commonly used stainless steel and the filler metal used to weld, respectively, it is 18-20 wt%. Evaporation and oxidation of Cr from the molten weld pool results in emission of carcinogenic hexavalent Cr (Cr+6 or chromate) in the fumes. This is a significant health hazard for the welders and necessitates considerable expense for ventilation systems. In some conditions relevant to DOD interests, such as cramped ship interiors, it is extremely difficult to ventilate effectively. Furthermore, any future reduction in the Permissible Exposure Limit (PEL) for chromate in welding fume, which is under consideration by OSHA, will exacerbate the situation. It is the objective of this proposal to develop a Cr-free consumable for welding austenitic stainless steel that provides mechanical properties and corrosion resistance comparable to the Cr-bearing consumable that are currently used. The approach to solving this problem considers that, if stainless steel (SS) is to be welded with a filler metal that is different in composition than the base metal, then the corrosion of the welded structure will be controlled by the phenomenon of galvanic corrosion. Furthermore, passive metals such as stainless steels usually corrode in a localized nature.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 2004
- Accession Number
- ADA438250
Entities
People
- G.s. Frankel
- J. C. Lippold
Organizations
- Ohio State University