Influence of Copper Addition on Sigma Phase Precipitation during Hot Deformation of Duplex Steel.

Grzegorz Stradomski,Dariusz Rydz,Arkadiusz Szarek

doi:10.3390/ma13071665

Abstract

The paper presents an experimental study on microstructure changes in duplex steel after hot deformation. Duplex steels and cast steels are characterized by a multiphase microstructure. They are relatively new materials with great contributions to the many fields of industries. Due to the fact of deforming two different phase austenite and ferrite those materials have a complex plasticity. This work is a continuation and complementation of previous works and is a significant supplement to information presented in them. The article concerns precipitation phenomena and changes in the microstructure of two grades of ferritic-austenitic steels: X2CrNiMoN25-7-4 and X2CrNiMoCuN25-6-3. Those steels have a very similar chemical composition, differing by only 2.5% copper content. An important aspect presented in the work is we observed that adding 2.5% copper prevented precipitation of the destructive sigma phase during the hot deformation.

Highlights

Steels and other iron alloys are very well known as construction materials, are widely-used and in the near future this will not change
The plasticity analysis of X2CrNiMoN25-7-4 steel showed that the delivery state was an important parameter affecting hot plastic deformability
The material deformed in preliminary tests, not subjected to solution-annealed, was characterized by about 2%–2.5% of the σ phase share and lower plasticity

Summary

Introduction

Steels and other iron alloys are very well known as construction materials, are widely-used and in the near future this will not change. Among the resistant-to-corrosion steels (Figure 1) and cast steels, the most modern and dynamically developing group are ferritic-austenitic alloys [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19]. For most resistant-to-corrosion steel grades, local corrosion (pitting, crevice, intergranular) is much more dangerous than general corrosion

Methods

Results

Conclusion