热轧盘条SWRH72A中间坯表面脱碳的影响因素

INFLUENCING FACTORS OF SURFACE DECARBURIZATION OF HOT ROLLED WIRE ROD SWRH72A INTERMEDIATE BILLET

利用加热炉、热模拟试验机研究了钢帘线用热轧盘条SWRH72A中间坯表面脱碳情况,分析了加热时间、加热温度及冷却速度对脱碳层深度的影响。结果表明,加热温度<800℃时,SWRH72A基本不发生脱碳;加热温度> 850℃时,脱碳层深度随温度的升高而增加。900℃保温时SWRH72A表面为完全脱碳;保温时间越长,SWRH72A脱碳层深度越大。脱碳深度与保温时间的平方根成线性关系。生产时应尽量降低加热温度,缩短高温段的保温时间,事故时尽量避开900℃待温;控冷工序提高冷却速度,以降低二次脱碳程度。

The surface decarburization of hot rolled w ire rod SWRH72 A used for steel cord w as studied by using heating furnace and thermal simulation test machine. The effects of heating time,heating temperature and cooling rate on the depth of decarburization layer w ere analyzed. The results show that there is no decarburization w hen the heating temperature is less than 800 ℃;the depth of decarburization layer increases w ith the increasing of temperature w hen the heating temperature is more than 850 ℃ . The surface of SWRH72 A is completely decarburized at 900 ℃ insulation;the longer the holding time is,the deeper the decarburization layer of SWRH72 A is. Decarburization depth is linear w ith the square root of holding time. The heating temperature shall be reduced as much as possible during production to shorten the holding time of high-temperature section,and 900 ℃ insulation shall be avoided in case of accident. In the controlled cooling process,the cooling rate should be increased to reduce the secondary decarburization degree.