Influence of the Interlayer Temperature on Structure and Properties of Wire and Arc Additive Manufactured Duplex Stainless Steel Product

Abstract

WAAM (wire and arc additive manufacturing) is becoming an increasingly popular method to produce components from metals, which are usually not so suitable for conventional production methods. One of the good examples is duplex stainless steels (DSSs), which are quite complex for welding and machining. Excessive ferrite amount is a common problem for them and controlling an interlayer temperature could offer a solution. However, using too low interlayer temperature will slow down the whole process and compromise one of the WAAM’s main advantages—the high productivity. The aim of this study is to find the relationship between interlayer temperature and process duration and to determine the influence of the interlayer temperature on product structure and other properties. Three samples (walls) were made using different interlayer temperatures (50 °C, 100 °C and 150 °C) and they were tested to analyze their surface texture, chemical composition, ferrite amount, the appearance of porosity and the hardness. Ferrite amount was higher and there was more porosity on lower interlayer temperatures, while there is no significant difference between surface texture and chemical composition for the samples. Considering the fact that higher interlayer temperatures provide a faster process, they should be preferred to produce duplex stainless steel products.

Preliminary Process and Microstructure Examination of Flux-Cored Wire Arc Additive Manufactured 18Ni-12Co-4Mo-Ti Maraging Steel

“…A shielding gas flow of less than 10 L/min causes global or local porosity, as also observed by Knezović et al [55], where the groups of pores are on the outer sides of the duplex steel wall. The use of a flow of 12 L/min in combination with slag covering the face of the layer guarantees no porosity, except for the arc ignition point.…”

“…Kozamernik et al [54] came to similar conclusions by examining the influence of the interpass temperature on the deviation from the geometry of the planned product, indicating that 150 • C is sufficient to obtain a deviation of less than 2%. Similarly, Knezović et al [55] indicate 150 • C as appropriate.…”

Combined effect of the interlayer temperature with travel speed on features of thin wall WAAM under two cooling approaches

“…In terms of the geometric point of view, Wang et al [15] showed that as the interlayer temperature increases, the width and height of the layer tend to enlarge and shorten, respectively. Furthermore, both Geng et al [10] (using an aluminium alloy) and Knezovic et al [16] (using duplex stainless steel) showed better surface finishing when higher levels of interlayer temperature were used, facilitating a possible machining step after deposition. However, this behaviour may not be the same for all materials, since Spencer et al [17] showed the opposite effect when a C-Mn steel was used as the feedstock.…”

Using Value Stream Mapping to Eliminate Waste: A Case Study of a Steel Pipe Manufacturer

“…The production of steel pipes is characterized by a relatively small amount of waste that is not recyclable and the need to use machines with a specialized structure and dimensions, or the technology used in the plant. Production takes place mainly with the use of electricity [26][27][28].…”