冷拔应变对304H钢丝扭转性能的影响

Influence of Cold Drawing Strain on Torsion Properties of 304H Steel Wire

研究了304H不锈钢丝Φ2.6 mm至Φ0.89 mm冷拔过程中组织演变和缺陷对不锈钢丝扭转性能的影响。结果表明:当钢丝冷拔真应变介于0~1.39时,扭转性能急剧下降、扭转次数减少;当冷拔真应变介于1.39~2.14时,扭转性能逐步回升,扭转次数增加。随着应变的施加,加工硬化导致位错塞积致使塑韧性变差,是扭转性能下降的主要因素,且此阶段{111}//ND织构含量增加也不利于扭转性能;随着冷拔真应变进一步增大,钢丝内部晶粒细化为超细晶粒导致强度进一步提升,塑韧性回复,是扭转性能回升的主要因素,且{111}//ND织构含量下降也有利于扭转性能。但冷拔真应变超过1.39之后,夹杂物平均面密度也同时增加,阻碍了钢丝扭转性能的进一步恢复。

The influence of structure evolution and defects of 304H stainless steel wire during the cold drawing process from φ2.6 mm toφ0.89 mm on torsion performance of stainless steel wire are studied.The results show that when the true cold drawing strain of the steel wire is between 0 and 1.39,the torsion performance decreases sharply and the number of torsion decreases;when the true cold drawing strain is between 1.39 and 2.14,the torsion performance gradually rises and the number of torsion increases.With the application of strain,work hardening leads to the deterioration of plastic toughness by dislocation plugging,which is the main factor for the decrease of torsional performance,and the increase in the content of {111}//ND texture at this stage is also not conducible to the torsional performance;as the strain is further increased,and the internal grains of steel wire are refined into ultra-fine grains,leading to further increase in strength and recovery of plastic toughness,which are the main factors for the rebound of torsion performance,and the decrease of{111}//ND texture content is also available to torsion performance.However,when the true cold drawing strain exceeds 1.39,the average areal density of inclusions also increases,which hinders the further recovery of the torsional performance of the steel wire.