含碳量与石墨形态对铬铜合金铸铁抗拉强度的影响

Effect of Carbon Content and Graphite Morphology on the Tensile Strength of Cr-Cu Alloyed Grey Cast Iron

采用树脂砂壳型浇注了两种含碳量的Cr-Cu铸铁圆试棒(直径30mm,长度450mm)。显微组织分析表明,该圆试棒浇口附近都由A型(大部分)和E型(少量)石墨组成,距浇口较远的尾端都由D型石墨组成。力学性能试验表明,该圆试棒浇口附近的硬度较低,而尾端的硬度较高;距浇口较远的一段的抗拉强度比距浇口较近一段的抗拉强度高10MPa左右。

The shell mold made from the phenol resin sand was used to produce Cr-Cu cast iron round test bars（in diameter of 30 mm,length 450 mm）with two kinds of carbon contents.The Microstructure analysis showed that in the test bar closer gate the A（majority）and the E-type（small）graphite formed,but in the test bar farther away from the gate D-type graphite was formed.The mechanical performance test showed that the hardness of the test bar closer gate is lower than that farther away from the gate,while the tensile strength of the section farther away from the gate is higher（about 10 MPa higher）than that of the section closer to gate.