东风_(4C)型机车柴油机机体焊接裂纹的研究

A study of weld cracks of engine blocks for DF_(4C) diesel locomotives

东风４Ｃ型机车柴油机机体采用铸焊结构。由于机体结构复杂，焊缝多且交叉，使得机体拘束应力大，机体经常产生焊接裂纹（ 主要是结晶裂纹） 。因此，消除焊接裂纹是控制机体质量的关键因素。本文主要介绍了焊缝金属中各种合金元素对产生裂纹的作用机理，以及各种合金元素相互作用关系；介绍了焊缝中某种合金元素浓度的计算方法，从定量的角度论证了焊接材料对主要化学成分的要求。

The engine block for DF 4C diesel locomotives uses cast welding structure. Because the structure of engine blocks is complicated and there are many weld seams that are cross, restraint stresses for engine blocks are big and weld cracks (mainly crystallization cracks) often occur in the engine block. Consequently, eliminating weld cracks is a key factor of controlling the quality of engine blocks. This paper mainly presents the mechanism of action on weld cracking of various alloying elements in the weld seam metal, the interaction among various alloying elements, the calculation method of the concentration of an alloying element in the weld seam, and demonstrates the require ments of weld materials for main chemical components quantitatively.