稀土硅铁合金对4Cr5MoSiV钢组织和性能的影响

研究了稀土硅铁合金在4Cr5MoSiV钢中的作用,在钢包中加入0.03%稀土硅铁合金,观察试样的显微组织、磨损形貌并测试其力学性能。结果表明,稀土硅铁合金的加入能起到细化晶粒的作用,显著提高4Cr5MoSiV钢的强度、冲击韧度和耐磨性。

激光熔凝对4Cr5MoSiV模具钢组织及性能的影响

采用激光熔凝对4Cr5MoSiV模具钢进行了表面改性处理,研究了激光熔凝处理对模具钢组织和力学性能的影响.结果表明,材料经熔凝处理后,由表及里依次为熔凝层、淬火层、热影响区和基体.熔凝层由典型的柱状晶组成,熔凝层和淬火层之间存在一层极薄的等轴晶区;淬火层的晶粒发生细化和超细化.强化层厚度达1.1mm,平均硬度比基体提高26%,热影响区的厚度为0.3mm左右,强化层的耐磨性和耐腐蚀性显著提高.

4Cr5MoSiV钢锻模挤压铸造熔炼技术研究

采用挤压铸造工艺生产4Cr5MoSiV钢锻模,可节约大量的模具钢和减少加工的费用,总结了挤压铸造用4Cr5MoSiV钢锻模的熔炼工艺要点,为发展锻模挤压铸造生产提供实际依据。

离子渗氮工艺参数对4Cr5MoSiV钢表层组织与性能的影响

目的研究离子渗氮的温度及时间对4Cr5MoSiV钢渗氮层组织、表面硬度及耐磨性的影响,获得提高硬度、耐磨性的最优工艺参数。方法对4Cr5MoSiV钢表面进行离子渗氮处理,渗氮温度分别为450、480、510、540℃,保温时间分别为5、10、15、20h。利用维氏显微硬度仪测量渗层深度及表面硬度;利用X射线衍射仪分析渗层物相组成;利用摩擦磨损试验机评价试样耐磨性;通过扫描电镜观察表面磨痕区域。结果离子渗氮渗层表面的物相主要为γ'-Fe4N相和ε-Fe2~3N相。在实验范围内,随着温度的升高或时间的增加,材料渗层深度、表面硬度增加,磨损率减少,但当温度过高或时间过长时,表面硬度下降,磨损率增加。在480℃的条件下进行20h离子渗氮的材料,表面具有最好的摩擦学性能,表面硬度为1147HV0.2,磨损率为2.13×10^-5mm^3/(N·m),渗氮层深0.24mm,化合物层深14.05μm,摩擦系数为0.45,磨损状态为磨粒磨损。结论离子渗氮是适合于变截面弹簧的表面强化方式,可以在材料表面形成具有一定厚度、均匀分布的渗氮层组织,显著提升表面硬度和耐磨性,降低摩擦系数。

压铸机压射冲头的改进

针对球墨铸铁压射冲头在压铸过程中的损耗量大、更换频繁的问题 ,进行了材质和制造工艺的改进 ,改进后的压射冲头的高温强度、硬度和耐磨性优于球墨铸铁压射冲头 ,其寿命比球墨铸铁压射冲头提高了 5

Behavior of Non-metallic Inclusions in Centrifugal Induction Electroslag Castings

In order to know the behavior of non-metallic inclusions in centrifugal induction electroslag castings (CIESC), non-metallic inclusions in 5CrMnMo and 4Cr5MoSiV1 were qualitatively and quantitatively analyzed. The largest size of inclusions in the casting and the thermodynamic possibility of TiN precipitation in steel were also calculated. The results show that sulfide inclusions are evenly distributed and the content is low. The amount of oxide inclusions in CIESC: 4Cr5MoSiV1 steel is close to the ESR steel and lower than that in the EAF steel, and there are some differences along radial direction. Nitride inclusions are fine and the diameter of the largest one is 3-1 mum. With the increase of the centrifugal machine's rotational speed, the ratio of round inclusions increases and the ratio of sharp inclusions decreases. According to the experiment and the calculation results, it is pointed out that the largest diameter of non-metallic inclusions in the CIESC 4Cr5MoSiV1 casting is only 6.6 mum, and [N%][Ti%] in 4Cr5MoSiV1 steel should be controlled less than 4.4x 10(-5) in order to further reduce the amount and size of TiN inclusions.