【摘要】 ML40Cr热轧盘条在用户使用过程中存在表面硬度高,模具损耗严重,冷镦开裂等问题。ML40Cr热轧盘条工艺控制:LF精炼时间高于40 min,白渣保持时间不低于15 min;连铸过程中,过热度控制在30℃以下,拉速稳定在2.4~2.5 m/min;轧制及冷却过程中,加热温度990~1 030℃,开轧温度950~980℃,减定径温度860~880℃,吐丝温度820~860℃,辊道速度8~14 m/min。分析ML40Cr合金冷镦钢盘条化学成分、非金属夹杂物、表面质量、组织结构和力学性能,严格控制夹杂物的形态、大小,避免表面结疤和线形缺陷的产生,保证金相组织为F+P,无异常组织存在。更多还原

【Abstract】 The problems that surface hardness is high,die wearing is serious and cold heading cracks exist while ML40Cr hot rolled wire rod is used by customer.ML40Cr hot rolled wire rod process control is as following: refine time of LF furnace is higher than 40 min,white slag keeping time is no less than 15 min.Superheat degree is controlled under 30 ℃ and casting speed is stabilized 2.4～2.5 m/min in the period of continuous casting.Heating temperature 990～1 030 ℃,start rolling temperature 950～980 ℃,size reducing temperature 860～880 ℃,wire rod laying temperature 820～860 ℃,roller speed 8～14 m/min in the period of rolling and cooling.The chemical composition,non-metallic inclusions,surface quality,structure and mechanical properties of ML40Cr alloy cold heading wire rod are analyzed.The shape and size of inclusions should be controlled strictly,to avoid the occurrence of surface scar and line defect,to guarantee microstructure is ferrite and pearlite,no existence of abnormal structure.更多还原