【摘要】 就汽车某外套筒裂纹失效进行了测试与分析研究，结果表明：裂纹产生的原因是外套筒表层存在大量的杂质元素并承受周期性的大应力。更多还原

【Abstract】 In this paper,the reason for the outer sleeve crack in vehicle is analysed and discussed The reswlt obtained shows that the outer sleeve erack is caused by both a certain amout of impurty elements in outer layer of the sleeve and periodic stress更多还原