淬火处理对激光选区熔化成形S136组织与性能的影响

Effect of quenching treatment on performance of S136 steel fabricated via selective laser melting

为了改善激光选区熔化(SLM)成形S136模具钢的性能,对SLM成形的试样进行淬火处理.采用X射线衍射(XRD)和扫描电子显微镜(SEM),研究淬火温度对SLM成形S136的微观组织、硬度和耐腐蚀性能的影响.结果表明:SLM成形的S136试样组织由马氏体和少量残余奥氏体组成,经过980、1 020、1 050和1 100°C的淬火处理之后,原晶界消溶,组织大部分转变为马氏体;淬火处理后试样的硬度得到改善,最高值达到54.24 HRC,比原始成形试样提高了近10%;淬火处理后试样原晶界消溶,耐腐蚀性元素分布均匀使得耐腐蚀性能得到了极大的提升,与原始成形试样相比,腐蚀失重量减少了近97%.优化淬火处理工艺后表明:采用1 050°C保温1 h并油淬的淬火处理条件,可以得到最佳的硬度/耐蚀性能匹配.

The quenching treatment was conducted to S136 mould steel fabricated by selective laser melting(SLM)in order to improve the properties.The effect of quenching treatment on the microstructure,hardness and anticorrosion properties was analyzed via X-ray diffraction(XRD)and scanning electron microscope(SEM).Results showed that the microstructure of S136 mould steel fabricated by selective laser melting was mainly martensite and retained austenite.The grain boundaries disappeared and dissolved into matrix after quenching treatment at 980℃,1 020℃,1 050℃and 1 100℃,and the microstructure transformed to martensite.The hardness of quenching treatment parts was improved to 54.24 HRC,which was increased by approximately 10%compared with unheated parts.The anti-corrosion properties were greatly enhanced due to the dissolution of grain boundaries and the evenly distribution of anti-corrosion elements.The mass loss of quenching treatment parts decreases to 97%of the as-produced parts.Results indicate that the best match of hardness and anti-corrosion properties can be obtained when quenching at 1 050℃for 1h.