碳元素及加热温度对SCM435钢氧化行为的影响

Effect of carbon element and heating temperature on oxidation behavior of SCM435 steel

随着汽车工业的高速发展,高强度螺栓钢作为汽车连接件的母材,需求量与日俱增。热轧过程中产生的氧化铁皮是影响高强度螺栓钢产品质量的重要因素。本文以SCM435钢为研究对象,利用扫描电镜、XRD和拉伸实验等检测手段,重点研究碳含量和开轧温度对SCM435钢表面氧化行为的影响规律。研究结果表明,含碳量较低时氧化铁皮分布均匀,主要由Fe_(2)O_(3)组成;含碳量较高时氧化铁皮主要由Fe_(3)O_(4)组成,分布不均匀,甚至会出现断带和裂纹。含碳量较高的螺栓钢更易产生较薄的氧化铁皮,加热过程中,氧化铁皮厚度随着加热温度的升高而降低;对于含碳质量分数0.1%的螺栓钢,存在临界温度,使氧化铁皮的厚度随着温度的升高先增加后减小。

With the rapid development of the automotive industry,the demand for high-strength bolt steel as a base material for automotive connectors is increasing day by day.The oxide scale generated during the hot rolling process is an important factor affecting the quality of high-strength bolt steel products.In this paper,the influence of carbon content and rolling temperature on the oxidation behavior of SCM435 steel were studied,using detection methods such as scanning electron microscopy,XRD,and tensile experiments.The research results show that when the carbon content is low,the oxide scale is evenly distributed and mainly composed of Fe_(2)O_(3);when the carbon content is high,the oxide scale is mainly composed of Fe_(3)O_(4),and the distribution is uneven,and even band breaks and cracks may occur.High-carbon bolt steel is more likely to produce thinner oxide scale.During the heating process,the thickness of the oxide scale decreases with the increase of heating temperature.For bolt steel with a carbon content of 0.1%,there is a critical temperature at which the thickness of the oxide scale increases first and then decreases with the increase of temperature.