Effects of Alloying Elements on High-Temperature Oxidation and Sticking Occurring During Hot Rolling of Modified Ferritic STS430J1L Stainless Steels

Abstract

In the present study, mechanisms of sticking that occurs during hot rolling of modified STS430J1L ferritic stainless steels were investigated by using a pilot-plant-scale rolling machine, and the effects of alloying elements on sticking were analyzed by the high-temperature oxidation behavior. The hot-rolling test results indicated that the Cr oxide layer formed in a heating furnace was broken off and infiltrated the steel, thereby forming Cr oxides on the rolled steel surface. Because the surface region without oxides underwent a reduction in hardness rather than the surface region with oxides, the thickness of the surface oxide layer favorably affected the resistance to sticking. The addition of Zr, Cu, and Ni to the ferritic stainless steels worked in favor of the decreased sticking, but the Si addition negatively affected the resistance to sticking. In the Si-rich steel, Si oxides were continuously formed along the interfacial area between the Cr oxide layer and the base steel, and interrupted the formation and growth of the Cr oxide layer. Because the Si addition played a role in increasing sticking, the reduction in Si content was desirable for preventing sticking.

Study of the High‐Temperature Oxidation Behavior of SUS430 Ferritic Stainless Steel Under Different Content of Water Vapor Atmosphere

“…[ 5 ] In addition, the nucleation and growth of Cr oxides are promoted by Si element in the steel. [ 6 ] Therefore, the microstructure of oxide scale is affected by the alloying elements, resulting in the sticking is also affected.…”

“…[5] In addition, the nucleation and growth of Cr oxides are promoted by Si element in the steel. [6] Therefore, the microstructure of oxide scale is affected by the alloying elements, resulting in the sticking is also affected.In hot rolling at high temperatures (500-1200 °C), [7] water is used as a coolant in several stages of hot rolling such as finishing rolling and laminar flow cooling, leaving the ferritic stainless steel in a high-temperature water vapor atmosphere. The effect of water vapor on high-temperature oxidation of ferritic stainless steel has been studied by some scholars.…”

In SituScanning Electron Microscopy Analysis of the Interfacial Failure of Oxide Scales on Stainless Steels and Its Effect on Sticking during Hot Rolling

“…7 However, during the hot rolling of ferritic STSs with a high Cr content, oxide flakes form and stick to the rollers, 4 deteriorating the surface of the STSs. 8,9 Because the surface quality is critical, STSs with indented surfaces have significantly diminished value. 10,11 Therefore, many engineers have tried to explain the fundamental mechanisms 12,13 and address the sticking failure problem with empirical control of alloying elements, 9 structural analysis, 11 processing parameter controls, 10 and replication of hot-rolling processes.…”

“…However, during the hot rolling of ferritic STSs with a high Cr content, oxide flakes form and stick to the rollers, deteriorating the surface of the STSs. , Because the surface quality is critical, STSs with indented surfaces have significantly diminished value. , Therefore, many engineers have tried to explain the fundamental mechanisms , and address the sticking failure problem with empirical control of alloying elements, structural analysis, processing parameter controls, and replication of hot-rolling processes . Kim et al suggested failure mechanisms with different types of commercial STSs on the basis of an ex situ elemental image analysis of the microstructure of the scale and the exposed fractured surface.…”