SWRH72A盘条拉拔断裂分析

Analysis on rupture of SWRH72A wire rod in drawing

用光学金相显微镜和扫描电子显微镜对SWRH72A盘条拉拔断裂试样进行一系列检验分析。结果表明:SWRH72A盘条组织中出现大量粗片状的珠光体是导致盘条拉拔断裂的直接原因。大量粗片状珠光体的形成与吐丝前后的冷却速度过慢等因素有关。严格控制吐丝前后的冷却速度,防止盘条堆积过密,可获得拉拔性能优越的索氏体组织。

A series of examinations and analysis have been made on the ruptured samples of the SWRH72A wire rod by way of optical metalloscope and scanning electron microscope （SEM）. Results show that large quantities of big flake perlite occurring in the structure of the wire rod is the cause directly to the rupture of the wire rod. Formation of large quantities of the flake perlite is closely dependent on the extremely low cooling rate before and after wire-drawing. By stringent control on the cooling rate before and after wire-drawing and prevention against heavily piling-up of the wire rod very desirable sorbite structures with excellent drawing property can be obtained.