不锈钢/碳钢复合钢筋内外温差轧制工艺研究

Research on Internal and External Temperature Difference Rolling Process for Stainless Steel/Carbon Steel Composite Bar

为考察轧件内外温差对不锈钢/碳钢复合钢筋热轧变形及性能的影响规律,通过有限元软件模拟不锈钢/碳钢复合钢筋热轧过程,并实验测量了不同温差下金属间的结合强度。结果表明,不锈钢/碳钢复合钢筋坯料的温度梯度影响着钢筋变形以及金属间的冶金结合。提高坯料表面温度,不锈钢外壳轧制后的不均匀程度增加,沿圆周方向壁厚差为0.32 mm,但两金属间形成更致密的冶金结合,剪切强度为247 MPa,较均温条件下提高了62.5%。坯料表面水冷提高了金属间的接触应力和芯部金属的三向应力,但等效应力/该温度下的屈服应力值随水冷时间延长而降低,水冷1.5 s后两金属的剪切强度为0,金属间不能形成冶金结合。

In order to investigate the effect of internal and external temperature difference on the deformation and properties of hot-rolling composite bars of stainless steel and carbon steel, the finite element software was used to simulate the hot rolling process and the metallurgical bonding strength was measured experimentally. The results show that the temperature gradient in the composite steel bars affects the deformation and the metallurgical bonding of the composite steel bars. By heating the billet surface, the unevenness degree of the stainless steel shell after rolling is increased and the wall thickness difference is 0.32 mm in the circumferential direction. But a more compact metallurgical bonding is formed between the two metals, and the shearing strength is 247 MPa which is increased 62.5% compared with uniform temperature. The contact stress between the metals and three-dimensional stress of the core metal are increased by water cooling the billet surface, but the equivalent stress/yield stress is decreased with water cooling time increasing. The shearing strength of the two metals is 0 after water cooling for 1.5 s and the metallurgical bonding cannot formed.