我厂在进行气动脱硫及型上球化处理二种新工艺的试验过程中,发现铸件上有其它铸造工艺中不常见的白斑与黑斑缺陷。球铁曲轴加工时,主轴承档和连杆轴颈档的外表层(均为上箱部分)出现白色斑块及黑色斑点状缺陷,简称白斑(图1)和黑斑(图2)。由于这些缺陷成批出现,严重地影响了产品质量和铸件的成品率。 I plant in the pneumatic desulfurization and the type of ball on the ball two new processes during the test found that castings are not common in other foundry process white spots and dark spots defects. When the ductile iron crankshaft is machined, white plaque and black spot-like defects appear on the outer surfaces of the main bearing and connecting rod journal (referred to as the upper box part), which are referred to as white spots (Figure 1) and dark spots (Figure 2). As these defects appear in batches, seriously affecting the quality of products and casting yield.