420不锈钢粉末温压成形工艺

Warm compaction technics of 420 stainless steel powder

对420不锈钢粉末进行温压,探索温压工艺参数对压坯密度的影响,并对温压与室温模压(添加0.7%硬脂酸锌作润滑剂)后压坯的密度和弹性后效进行比较。实验结果表明:最佳粉末加热温度为90℃,最佳模具温度为120℃,最佳润滑剂含量为0.7%(质量分数)。在该工艺条件下,当压制压力为784 MPa时,压坯密度达到6.86 g/cm3;经1 130℃烧结后样品密度略有下降,为6.83 g/cm3,硬度为HRC33。温压压坯密度比室温模压的提高约0.2 g/cm3,温压后压坯弹性后效较室温模压小。

420 stainless steel powders was warm compacted. Influences of processing parameters of warm compaction on green density of 420 stainless steel were studied. Moreover, warm compaction was compared to traditional pressing （adding 0.7% zinc stearate） from the green density and the delayed elasticity. The results show that the optimum powder heating temperature and die temperature are 90 ℃ and 120 ℃, respectively. The optimum lubricant content in powders is 0.7% （mass fraction）. For 420 stainless steel powders, the density of 6.86 g/cm^3 can be achieved under the optimum process at 784 MPa. The density is slightly declined to 6.83 g/cm^3 and the hardness is HRC33 after solid state sintering at 1 130 ℃. The green density of warm compaction is about 0.2 g/cm^3 higher and the delayed elasticity is smaller than that of traditional pressing.