Evolution of the Plasticity of Some Low Carbon Steels, Subjected to Directed Cooling from High-temperature

Abstract

An important influence factor for the plasticity of the low carbon steels is the cooling speed value after heating treatment. It is important to be chooses the optimal cooling regime for these materials because the steels have been laminated at high temperature or, the steels have been heated at high temperature after lamination process. There were considered two groups of samples of two low carbon steels, each group had eight samples. Three different mediums for directing of the cooling process were considered and the properties of the steels have been modified. After an experimental program, the values obtained were used to determine the variation between these variables corresponding to two kinds of steels (coded: Steel 1 and Steel 2).

Plasticity Behavior of the Steel Depending on the Cooling Regimes in the Case of a Non-Conventional Treatments

“…In table 3, the cooling speed values for each different cooling conditions influences the mechanical properties of the steel. The results obtained after the experimental scheme [1,3] Flow Limit or High Deformation Limit is very important for steels used for metal construction or for armatures. The resistance of the metallic bridge or the resistance of the wall in construction depends on the flow limit of the steel with a low content of Carbon.…”

“…The samples were heating at the different temperatures: T1 = 850ºC (for the first batch of samples), T2 = 900 o C (for the second batch of samples), T3 = 950 o C (for the third batch of samples) and T4 = 1000 o C (for the last batch of samples). Three cooling regimes [1,3] Traction tests at the room temperature were carried out according to ASTM: E8M-11 standard [1,3,17], while those related to elevated temperatures were carried out according to ASTM: E21-09 [1,3,5,10,14,16]. Charpy impact tests for resilience determination were carried out according to ASTM: E23-07ae1 standard [11].The preparation of metallographic specimens was conducted according to ASTM E3-11 standard [1,3,6,8,[12][13][14][15]18].…”

“…Three cooling regimes [1,3] Traction tests at the room temperature were carried out according to ASTM: E8M-11 standard [1,3,17], while those related to elevated temperatures were carried out according to ASTM: E21-09 [1,3,5,10,14,16]. Charpy impact tests for resilience determination were carried out according to ASTM: E23-07ae1 standard [11].The preparation of metallographic specimens was conducted according to ASTM E3-11 standard [1,3,6,8,[12][13][14][15]18]. All of mentioned standards can be found in Annual Book of ASTM Standards (2012) [1].…”

“…The increasing rapidly of the deformability between 600 and 800 °C is due to inter-crystalline displacements and re-crystallization of steel. At the same time, the deformability of the steels depends on the carbon content [1][2][3]5].…”

“…The steels with low carbon content have high plasticity properties below 550 C and the thermal stresses will not leads to the formation of cracks [1]. The paper focuses on directed fast cooled steels strips for automotive application after hot laminated process [3].…”