ABSTRACT

For manufacturing of steel wires, tubes and profiles in hot rolling mills, the toughest conditions occur in the front rolling stands where the mechanical load comes along with a constant change of hot rolling stock and cooling liquid. Conventional roll materials as pearlitic or acicular cast irons are not able to overcome these intense conditions because of their lack of ductility. A fine selection of alloying elements leads to a new material with a microstructure uniting bainite, austenite and martensite inducing high hardness and strength, without lacking elongation. For this purpose, a full-factorial design of experiments was created consisting of three alloying elements in two concentrations each. The alloys were cast, heat-treated and underwent extensive investigations on mechanical properties and microstructure. The results were analysed and implemented in mathematical models whose combination and optimisation led to the identification of the ideal alloy meeting the required strength, hardness and elongation.

摘要

对于在热轧机中制造钢丝、管材和型材，最严酷的条件发生在前轧机机架，在那里机械载荷伴随着热轧材和冷却液的不断变化。珠光体或针状铸铁等传统轧辊材料由于缺乏延展性而无法克服这些苛刻条件。合金元素的精细选择导致新材料具有结合贝氏体、奥氏体和马氏体的微观结构，从而导致高硬度和强度，且不缺乏延伸率。为此，创建了一个全因子实验设计，其中包含三种合金元素，每种元素有两种浓度。对合金进行铸造、热处理，并对其机械性能和微观结构进行了广泛的研究。