氦气冷却真空自耗冶炼GH738合金冶金质量

Metallurgical Quality of GH738 Alloy Melting in VAR Furnace with Helium Gas Cooling

本文介绍宝山钢铁股份有限公司特殊钢分公司最新引进的10吨氦气冷却真空自耗炉主要特点及熔炼GH738合金的冶金质量。由于采用氦气冷却、瞬时熔速控制和功率因素液滴短路控制弧长等最新技术,显著改善了GH738合金的宏观偏析,合金锭各部位合金元素均匀分布,H、O、N含量分别降低至1．4ppm以下、5ppm以下和50ppm以下,Mg的收得率提高,控制稳定,分布均匀。结果显示:与普通VAR工艺相比,氦气冷却VAR新工艺能显著改善合金的宏观偏析,并具有更好的脱气效果,使易烧损元素得到较好控制。

This article introduced the characteristics of a 10-ton VAR furnace with helium gas cooling and metallurgical quality of GH738 alloy melt with the VAR furnace. The latest techniques have been adopted, including helium gas cooling, instantaneous melting speed control, power-factor-referenced arc length control via droplet short circuit, etc. , which remarkably improved the macrosegregation of GH738 alloy and made alloy elements be distributed evenly in ingot. The results showed that hydrogen, oxygen and nitrogen contents have been decreased to less than 1.4 ppm, 5 ppm and 50 ppm respectively and the yield of magnesium has been increased since the element was stably controlled. Compared with routine VAR process, the new VAR process with helium gas cooling can remarkably improve the macrosegregation of alloys and achieve better degassing result, which keeps easy-overtired elements under well control.