12V240Z 型柴油机曲轴所用的材料为35CrMoA 合金结构钢。该材料经调质处理后的机械性能如下:抗拉强度σb≥80公斤力/毫米~2;屈服强度σs≥60公斤力/毫米~2;延伸率δ5≥12%;断面收缩率ψ≥40%;冲击韧性αk≥6公斤力·米/厘米~2;顾度为 HB250～280。为提高曲轴的疲劳强度和耐磨性能,对曲轴进行氮化处理,处理后的氮化层深度>0.4毫 12V240Z diesel engine crankshaft material used for 35CrMoA alloy steel. The material after quenched and tempered mechanical properties are as follows: tensile strength σb ≥ 80 kg / mm ~ 2; yield strength σs ≥ 60 kg / mm ~ 2; elongation δ5 ≥ 12%; reduction of area ψ ≥ 40 %; Impact toughness αk ≥ 6 kg force · m / cm ~ 2; Consistency HB250 ~ 280. In order to improve the crankshaft fatigue strength and wear resistance, the crankshaft nitriding treatment, nitriding layer depth> 0.4 milliliters