825合金斜轧穿孔过程的温升和应力分布

Temperature Rise and Stress Distribution of 825 Alloy During Cross-Rolling Piercing Process

针对镍基825合金斜轧穿孔生产无缝钢管过程中产生的裂纹现象进行研究分析,通过借助金相组织观察和有限元分析手段对开裂的原因进行了探讨,认为热加工过程中局部温升和增大的剪切应力是导致开裂的主要原因。此外,从管坯初始孔径、初始温度、顶头润滑条件等3个工艺参数的角度对管坯中心开裂现象进行了规律性研究,发现影响管坯局部温升的最主要因素是顶头润滑条件,通过降低顶头摩擦系数可明显降低局部温升现象,而工艺参数对最大切应力的影响并不明显。因此认为斜轧穿孔过程导致的温升是管坯质量控制的最关键影响因素。

The cracks in the process of cross-rolling piercing production of domestic 825 alloy pipes were studied.The causes of the cracks were discussed by metallographic observation and finite element analysis methods,and it is found that the local temperature rise and increased shear stress is the main cause of cracking.In addition,from the perspective of three process parameters such as the initial diameter of the tube,the initial temperature,and the lubrication conditions of the plug,the regularity of the cracking phenomenon of the tube was studied,and the most important factor affecting the local temperature rise of the tube is the plug lubrication condition.And the local temperature rise phenomenon can be significantly reduced by reducing the friction coefficient of the plug.However,the influence of process parameters on the maximum shear stress is not obvious.Therefore,it is believed that the temperature rise caused by the cross-rolling piercing process is the most critical influencing factor for the quality control of the tube.