The effect of processing parameters on the properties of multi-phase advanced high strength steel grades

研究领域：材料工程-金属和合金汽车制造商不断发展和开发新的解决方案，以制造更好的汽车，更省油，更实惠，更安全。钢种的发展对汽车工业的发展起着至关重要的作用。近年来，汽车用钢的等级发生了翻天覆地的变化，钢铁制造商应该做好准备，为日益增长的汽车工业服务。未来的汽车一定是安全、环保、耐用和便宜的。因此，这些汽车对钢材的要求是：高强度钢，限制重量，保证安全。镀锌，经久耐用。通过强大的工业流程为汽车行业生产新钢种，以确保始终如一的机械性能，这本身就是对钢铁生产商的一个挑战。多年来，带钢加工生产线技术已经发展到符合钢等级的新要求。随后，新的钢种需要更复杂的热循环和热技术。今天，我们可以确定三个重要的里程碑：2000年：双相（DP）级要求快速冷却阶段。2007年：新牌号，如TRIP（转化诱导塑性），必须在处理DP级钢的同一条连续镀锌线（CGL）上进行加工。2012：采用多相钢牌号的更高机械性能（TS大于1000mpa），如淬火和分区，需要额外的浸泡后热处理和更高的退火温度。热循环的每个阶段都会影响钢的力学性能。新型高级高强度钢（AHSS）牌号在浸渍阶段后的加工复杂性增加，因为每种AHSS牌号对热循环的要求不同。因此，连续镀锌线（CGL）需要有足够的灵活性来处理所有这些等级。由于SUK-PT正准备对其现有的CAPL进行投资，以使其成为结合CGL和CAL能力的“摆动线”，因此对于强大的工业工艺来说，关于新的汽车AHSS等级加工的详细知识是必须的。该博士论文的目的是研究“工艺参数对回火马氏体和回火贝氏体混合组织的多相ahss等级性能的影响”。

Research Area: Materials Engineering - metals and alloysCarmakers are continuously evolving and developing new solutions to make better cars, which are more fuel efficient, affordable and safer. The development of steel grades is a key contributor towards the evolution of the automobile industry. There has been a sea change in automotive steel grades over recent years, and steel makers should be prepared to serve the growing automobile industry.Tomorrow's car must be safe, environmentally friendly, durable and cheap. As a result, the requirement of steel for these cars is to be:. High-strength steel to limit weight and preserve safety. Galvanised for durability. Produced with reduced operational costsProduction of new steel grades for the automotive industry through robust industrial process in-order to ensure consistently identical mechanical properties is, in itself a challenge to steel producers.Over years, strip processing line technologies have evolved to match the new requirements of steel grades. Subsequently, new steel grades demanded more sophisticated thermal cycles and thermal technologies. Today, we can identify three major milestones:. 2000: Dual Phase (DP)-grades requesting rapid cooling stages. 2007: New grades, such as TRIP (Transformation Induced Plasticity), must be processed on the same continuous galvanising line (CGL) that processes DP grade steels. . 2012: Higher mechanical properties (TS greater than 1000 MPa) using multi-phase steel grades, such as Quenching & Partitioning, require additional after-soaking heat-treatment together with a higher annealing temperature.Each stage of the thermal cycle will influence the mechanical properties of the steel. Processing of new AHSS (Advanced High strength Steel) grades increases in complexity after the soaking stage of the process as the requirements of the thermal cycle are different for every family of AHSS. Therefore, a continuous galvanising line (CGL) needs to have enough flexibility to process all these grades.Since SUK-PT is preparing for an investment in its existing CAPL for making it a "swing-line" to combine CGL and CAL capabilities, detailed knowledge on the processing of new AHSS grades for Automotive is a must for a robust industrial process. This PhD proposal aims to generate knowledge on "The effect of processing parameters on the properties of multi-phase AHSS-grades having a mixed microstructure of Tempered Martensite and Tempered Bainite".