含Cr油罐钢的碳化物析出研究  

Study on Carbide Precipitation of Cr Bearing Steel for Oil Tank

作　　者：李国宝[1] 

机构地区：[1]济钢集团有限公司

出　　处：《宽厚板》2015年第1期18-21,共4页Wide and Heavy Plate

摘　　要：研究了油罐用含Cr低碳合金钢在950℃淬火+650℃回火以及不同保温时间条件下Cr的碳化物析出,从而解释了不同调质工艺性能的变化。Cr在回火后容易形成M7C3及M23C6碳化物,这两种碳化物处于亚稳状态,随回火时间延长容易聚集长大,并且形态呈现长条状。对不同回火保温时间下含Cr钢第二相粒子析出行为的研究发现,在1 min/mm的保温时间下,没有发现含Cr的碳化物析出;随着保温时间的增加,Cr的碳化物快速析出并迅速长大;在3 min/mm的保温时间下,含Cr的碳化物尺寸达到300 nm。因此,低碳调质高强度合金钢生产必须采用合适的调质工艺,适当缩短回火保温时间,才能避免Cr的碳化物聚集长大引起的强度及塑性降低。The article describes the study on Chromium carbide precipitation of Cr bearing low carbon alloying steel for oil tank under the conditions of various holding times after quenching at 950 ℃ and tempering at 650 ℃,interprets the performance variation of various quenching and tempering processes. Cr element tends to form carbide of M7C3 or M23C7. Both the carbides in metastable state tend to congregate and grow into a strip shape. By investigating the precipitation behavior of secondary phase particles in Cr bearing steel under the conditions of different tempering holding times,no Chromium carbide precipitation is found under the holding time of 1 min / mm,and the Chromium carbide precipitates and grows rapidly,the size of Chromium carbide reaches to 300 nm under the holding time of 3 min /mm. Therefore,the quenched and tempered type high strength low carbon alloying steel shall have to be produced with proper quenching and tempering process and reduced tempering holding time in order to prevent strength and plasticity from reduction due to congregation and growth of Chromium carbide.

关 键 词：低碳合金钢 调质 淬透性 碳化物 

分 类 号：TG161[金属学及工艺—热处理] TG142.1[金属学及工艺—金属学]