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本文研究了GH30合金管内壁裂纹形成的机理,考查了管坯加热温度、轧辊转速、顶头预热温度和轧辊倾角等工艺因素对荒管内壁裂纹的影响.研究结果表明:穿孔中由于管坯加热温度偏高,顶头同金属形成一种粘结摩擦,使荒管内壁表层金属的瞬时温升很高,导致晶界弱化和“失塑”.在变形过程中各种应力的综合作用下,使内壁金属极易破坏而形成沿晶发展的粘结摩擦热致裂纹.
In this paper, the mechanism of crack formation in the inner wall of GH30 alloy tube was studied, and the influence of process factors such as tube heating temperature, roll rotation speed, head preheating temperature and roll inclination angle on the internal wall crack of inshore tube was investigated.The results show that: The temperature is high, the head with the metal to form a bond friction, so that shortage of the inner surface of the tube wall temperature instantaneous high, leading to grain boundary weakening and “plastic.” In the deformation process under the combined effect of various stresses, so that The inner wall metal is easily damaged to form intergranular bond friction thermal cracking.