SVP40CES1钢连杆的气体渗氮

Gas Nitriding for SVP40CES1 Steel Connecting Rod

SVP40CES1钢连杆需进行气体渗氮，要求渗层深度≥0．3mm，在0．05mm深度处硬度≥1000HV1，脆性Ⅰ～Ⅱ级。经多次渗氮工艺试验，最终确定该连杆采用新型BBN渗氮炉进行三段渗氮：490℃×3h×25％，540℃×16h×25％，以及530℃×21h×35％。结果，连杆的渗层深度为0．34mm，0．05mm深度处硬度为1096HV1，其他质量指标也达到了要求。

Connecting rod, made of SVP40CES1 steel, must be gas nitrided to form a ease which has depth of 0.3 mm or more, as high hardness as 1 000 HV1 or more at a depth of 0.05 mm, brittleness of grade 1 or 2, etc. After test for nitriding process was performed many times, it was finally determined that the connecting rods were three-stage nitrided at 490 ℃ for 3 h with 25% dissociation,540 ℃for 16 h with 25% dissociation,and 530 ℃ for 21 h with dissociation 35% in a new type of BBN nitriding furnace. The results indicate that the ease depth is 0.34 ram, the hardness at a depth of 0.05 mm is as high as 1 096 HV1, and that other nitriding quality criteria also meet the requirements for the connecting rod.