小口径双相不锈钢轴套的离心铸造工艺

Manufacturing of Duplex Stainless Steel Sleeves with Small Caliber by Centrifugal Casting

介绍了双相不锈钢的特性、轴套的尺寸参数及离心铸造特点,探讨了裂纹、重皮及气孔等缺陷的预防思路及要点。降低离心转速,防止热裂缺陷效果显著,但需提高铸型的蓄热能力。对于牌号为1.4460的双相不锈钢,在凝固阶段可进一步降低转速。提高脱模温度,也有助于减轻热裂缺陷。提高铸型工作温度,采用具有等比渐变截面浇道的海螺浇口及控制初始浇注速度以满足初始铺型厚度,对防止小口径铸钢套类铸件产生重皮缺陷有较好的效果。

Characteristic of duplex stainless steel, dimensional parameter of sleeves and centrifugal casting technique were described. Key points in preventing crack, double skin and air hole were presented . Through decreasing centrifugal speed, it is effective for preventing hot crack, however, heat reserving capacity of the mould should be improved to prevent liquid alloy from overflowing. During solidification process of 1. 4460 duplex stainless steel, rotating speed could be further decreased. Meanwhile, increas ing pullmold temperature, hot crack could be relieved. Through increasing mould temperature, adop ting conch gate with analogy gradation section and controling initial pouring speed to meet initial thick ness, double skin in castings such as cast steel jacket with small caliber could be eliminated .