Higher Productivity In Forming High-alloyed Steel By Temperature Insensitive Friction Behavior

Abstract

Like in many other production technologies, a broad process window for metal forming is desired. The goal is always a stable process chain. One of the key aspects for metal forming are stable tribological conditions. Instabilities can be caused by, amongst others, different material batches, change in temperature during the production process, different lubricant amounts and different stroke rates. At the beginning of a production run, the tribological stability suffers from transient temperature effects caused by plastic and frictional work and a viscosity drop of the lubricant. To control the tribology, different strategies are suitable: changing the oil type, the oil amount, the blank holder force or the stroke rate. Within the EU-project ASPECT, control strategies on blank holder forces are developed as well as lubricants with improved stability on their behaviour as a function of temperature. This paper will focus on the latter. In preliminary ball on plate test the friction and wear of lubricant formulations were investigated and compared to a Reference lubricant. Followed by strip drawing and forming tests. Finally, the concept is proven in trials on a demonstrator line, which is close to serial production.

On the Use of Advanced Friction Models for the Simulation of an Industrial Stamping Process including the Analysis of Material and Lubricant Fluctuations

“…In industry, a constant Coefficient of Friction (CoF) of 0.15 has been traditionally used for a steel part [2,3]. However, several studies have shown that the friction coefficient depends on various factors including contact pressure [4][5][6], sliding velocity [3,4], lubricant type and amount [7,8], temperature [8,9], strain [3], and tool and sheet roughness [6,[10][11][12]. Different studies have analyzed these influences [6,[8][9][10][11][12][13][14].…”

“…However, several studies have shown that the friction coefficient depends on various factors including contact pressure [4][5][6], sliding velocity [3,4], lubricant type and amount [7,8], temperature [8,9], strain [3], and tool and sheet roughness [6,[10][11][12]. Different studies have analyzed these influences [6,[8][9][10][11][12][13][14]. It was found that a decrease in the friction coefficient corresponds to an increase in sliding velocities and contact pressures [13].…”

An Econometric Model of the Operation of the Steel Industry in POLAND in the Context of Process Heat and Energy Consumption

“…The consumption of resources and energy in the steel industry impacts process productivity. Process productivity in the context of energy and carbon consumption in the steel industry was written about by Marshall [14], Wang and Tang [15], Panigrahi [16], Maddalena [17], Saha [18], Aha [19], Serebrennikova [20] and Kuriakose and Kuriakose [21], among others.…”