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采用预先热处理以获得中间类型的组织,可以改变钢的冷变形性。但是冷塑性变形时,这些组织塑性提高的原因,尚不清楚。碳素钢大试样热处理时,奥氏体在中间区转变的结果,难以得到单一贝氏体组织。因为这些钢中间转变区域不明显,在中间区及珠光体区的最大转变速度是一样的,因此中间类型的转变发生在珠光体转变之前。本文研究了45钢和60钢中间区域组织形成的特点以及这些组织对提高钢的塑性、因而改善在冷态下用液压机压制时的变形性的作用。液压机压制时,利用奥氏体等温转变图按规范1:在880℃(45钢)和950℃(60钢)奥氏体化,在盐槽(55%NaN03+45%KNO_3)中于310℃(45钢)和340℃(60
Pre-heat treatment to obtain intermediate types of tissue can change the cold deformability of the steel. However, the reason for the plasticity of these tissues during cold plastic deformation is not clear. Carbon steel large sample heat treatment, the results of the transformation of austenite in the middle, it is difficult to get a single bainite. Because of the insignificant mid-transformation region of these steels, the maximum rate of change in the middle and pearlite regions is the same, so the transition of the middle type occurs before the pearlite transformation. In this paper, the characteristics of the formation of microstructure in the middle of 45 and 60 steel and the effect of these microstructures on improving the plasticity of steel are studied, which can improve the deformability of hydraulic steel in cold state. Austenitic isothermal transformation diagram according to Specification 1 when pressed by a hydraulic press Austenitizing at 880 ° C (45 steel) and 950 ° C (60 steel) at 310 ° C in a salt bath (55% NaNO 3 + 45% KNO 3) (45 steel) and 340 ℃ (60