我厂生产的高速平缝机零件多数采用20Cr钢制造,根据各零件的技术要求,采用不同的碳氮共渗工艺。渗层一般在0.35mm以上的零件,多数采用840℃共渗工艺,而浅层采用760℃或780℃共渗工艺。如我厂生产的SJJ、GC15-1等高速平缝机的针杆连杆、抬牙前曲柄、挑线杆、挑线连杆等零件,要求变形小、硬度高,渗层在0.40mm左右。以往都采用 I plant the production of high-speed sewing machine parts most of the use of 20Cr steel manufacturing, according to the technical requirements of each part, using different carbonitriding process. Seepage layer is generally above 0.35mm parts, the majority of the use of 840 ℃ co-permeation process, while the shallow 760 ℃ or 780 ℃ co-infiltration process. If I plant the SJJ, GC15-1 and other high-speed sewing machine needle bar connecting rod, crank lift before, pick the line rod, take the line connecting rod and other parts, requiring small deformation, high hardness, infiltration of about 0.40mm . Used in the past