Super Quality Melts for State-of-the-Art Steel

多年来，在浇注和凝固之前清除钢液中的夹杂物一直困扰着钢铁制造商。较大的夹杂物团聚物具有足够的浮力，如果在凝固之前给予足够的时间，它们可以漂浮到钢液表面。然而，小于~60微米的较小夹杂物团簇的浮出速度如此之低，以至于它们像其他夹杂颗粒一样被困在钢液中，并最终停留在凝固钢中。所有这些夹杂物对钢的性能都是非常有害的。我们一直致力于纠正这个问题，通过考虑如何在钢液中产生微气泡群，以便拦截各种大小的夹杂物，并将它们从不同的钢液“浴缸”中移开。使用数学和全比例水模型，我们已经能够向我们的工业合作伙伴RTFT、RTMP和NSC演示一种可能的解决方案。他们热情地同意支持这一倡议，这将代表a)改善RTMP的金属粉末质量，b)改善RTFT的金属粉末夹带(MPE)，以及c)改善NSC的钢材质量。这个CRD项目将首先确认我们迄今的水模型结果，使用我们用于RTIT和NSC的全尺寸中间罐系统，以及RTMP中间罐的三分之一比例模型。同时，一种低温、非润湿、低熔点的合金(“Cerrolow 136”)将被用来确认这种新的“微泡清洗”技术的价值，该技术使用包含受控气体喷射的循环液态金属回路。然后，我们将为新日铁公司(NSC)以及力拓金属粉末(RTMP)和力拓Fer&Tiane(RTFT)工厂设计同等的钢液测试。鉴于RTMP是北美汽车行业最大的金属粉末供应商，而RTFT也是汽车零部件供应商，这将是首先受益的，以及他们的次要金属零部件供应商。与NSC的这项合作将提高加拿大炼钢专业技术的竞争力，并导致该技术的早日采用，并有望大幅改善未来的钢铁质量和性能，使所有人受益。

Ridding inclusions from liquid steel prior to casting and solidification has vexed steelmakers for many years. Large inclusion agglomerates are sufficiently buoyant, that they can float up to the surface of the liquid steel, if given sufficient time, prior to solidification. However, the smaller inclusion clusters of less than ~60 microns have such low float-out velocities that they remain trapped in the liquid steel, as do other entrained particles, and end-up in the solidified steel. All these inclusions can be very harmful to a steel's properties. We have been working on redressing this problem, by considering how to create microbubble swarms in liquid steel, so as to intercept all sizes of inclusions, and displace them from various "baths" of liquid steel. Using mathematical and full scale water models, we have been able to demonstrate a possible solution to our industrial partners, RTFT, RTMP, and NSC. They enthusiastically agree to support this initiative which will represent a) improved metal powder quality at RTMP, b) improved removal of MPE (metal powder entrainment) at RTFT, and c) improved steel quality at NSC. This CRD program will start, by confirming our water model results to date, using our full scale tundish systems for RTIT and NSC, and a one-third scale model of the RTMP Tundish. Simultaneously, a low temperature, non-wetting, low melting point alloy ("Cerrolow 136"), will be used to confirm the value of this novel "microbubble cleaning" technology, using a recirculating liquid metal loop incorporating controlled gas injection. We will then design equivalent liquid steel tests for Nippon Steel Corporation(NSC), and for the Rio Tinto Metal Powders (RTMP) and Rio Tinto Fer & Titane (RTFT) plants. Given that RTMP is the largest supplier of metal powders to the automobile industry in North America, while RTFT is also a supplier of auto-parts, this will firstly benefit, as well as their secondary metal parts suppliers. This collaboration with NSC will increase the competitiveness of Canada's steelmaking expertise, and lead to the early adoption of the technology, with the promise of dramatic improvements for future steel quality & properties, for the benefit of all.