Detailed Explanation of Forging Process: Full Process Analysis of Hot Forging, Cold Forging and Warm Forging

Detailed Explanation of Forging Process: Full Process Analysis of Hot Forging, Cold Forging and Warm Forging

Forging processing is a core industrial process that causes plastic deformation of metal billets through external force to obtain parts with required shape, size and performance. It is widely used in machinery, automobile, aviation, mining and other fields. Among them, hot forging, cold forging and warm forging are the three most mainstream processes. Based on the differences in processing temperature, the three processes have their own focuses in terms of process flow, characteristics and application scenarios. The following will detailedly analyze the full process and core points of the three processes to help industry practitioners accurately understand and select the right process.

Hot forging is the most widely used forging process, and its full process is divided into five steps: billet preparation, heating, forging forming, cooling and post-treatment. First, select metal billets of suitable materials and remove surface scale and impurities; then heat the billets above the metal recrystallization temperature (usually 800-1200℃) to improve their plasticity and reduce resistance; then apply external force through a forging press to form the billets in the mold; after forming, cool them slowly to avoid cracks caused by too fast temperature drop; finally, obtain qualified parts through post-treatment such as deburring, annealing and flaw detection. Its advantages are good plasticity, low forming difficulty and ability to process complex special-shaped parts; the disadvantage is that heating is prone to produce scale and the precision is slightly low.

Cold forging is a forging process carried out at room temperature, and its process is simplified into billet pretreatment, forging forming and post-treatment. First, perform pickling, phosphating and lubrication treatment on the billets to reduce processing resistance and protect the surface; without heating, directly apply pressure through a high-precision forging press to cause plastic deformation of the billets; after forming, improve the strength and precision of parts through shot blasting, correction, heat treatment and other processes. The advantages of cold forging are smooth surface, high dimensional precision, no need for complex post-treatment and high material utilization rate; the disadvantages are poor plasticity, only suitable for small and simple-shaped parts, and high requirements on equipment pressure.

Warm forging is a process between hot forging and cold forging. Its process combines the characteristics of both, and the core is to control the processing temperature (usually 200-800℃). After the billet is properly heated, it is lubricated, then formed by a forging press, and finally cooled and post-treated. It combines the plasticity advantage of hot forging and the precision advantage of cold forging, which not only reduces the generation of scale, but also lowers the forming difficulty and avoids the equipment loss caused by cold forging. It is suitable for parts with medium requirements on precision and performance, and has outstanding cost performance.

In summary, the three forging processes have their own advantages and disadvantages: hot forging is suitable for complex parts, cold forging for high-precision small parts, and warm forging balances precision and efficiency. In actual production, it is necessary to select a suitable process plan according to part requirements and material characteristics to ensure the balance between product quality and production efficiency.