The relatively large silicon concentration in many TRIP-assisted steels causes the formation of hard, adherent oxides making it difficult to implement surface cleaning prior to hot-rolling. This results in a poor surface finish. The stronger adhesion comes from that fact that the silicon undergoes a eutectic reaction between FeO and Fayalite (Fe
2SiO
4). This reaction occurs at typical hot-rolling temperatures and leads to the penetration of the eutectic into the steel, thereby anchoring the oxide. Residual FeO left on the surface of the eutectic then changes into Fe
2O
3which is the red oxide that gets rolled into the surface, producing an ugly finish on the steel.
Crash-reinforcement bar in the door panel |
Crash-reinforcement bar in the door panel |
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Crash-reinforcement bar in the door panel |
Crash-reinforcement bar in the door panel |
Crash-reinforcement bar in the door panel and the strong-steel pillar |
Crash-reinforcement bar in the door panel |
"Body in white" |
Crash-reinforcement bar in the door panel |
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"Body in white" |
"Body in white" |