2 Piece Forged Wheels Causes Of Crack Formation

2 Piece forged Wheels Causes of Crack Formation

The reasons for the formation of cracks in the wheel forging should first understand the process in order to find out the objective conditions of the crack formation. Secondly, the state of the crack itself should be observed, and then the necessary microstructure analysis and microstructure analysis should be carried out. For example, for the production of cracks for the forging, rough analysis may be: 1. due to over burning; 2. due to soluble metal infiltration of matrix metals (such as copper into the steel); 3. stress corrosion cracking; carbon. This can be further identified from process and organizational analysis. For example, in the heating of copper after heating steel or the two mixed heating or steel in the copper content is too high, it may be crisp. From the microstructure point of view, copper crisp cracking in the grain boundary, in addition to finding cracks, but also to find bright copper network, and simply burned grain boundary can only find the oxide. Stress corrosion cracking occurs after acid picking, and at high magnification, the crack is expanded in a dendritic shape. For a serious decarburization of the forging, a thicker decarburization layer can be observed on the test piece. Wheel forging crack and folding of the identification, not only from the stress and deformation conditions, can also be from the low magnification and high power to distinguish. The general crack and the flow line into a certain angle, and folding near the streamline and folding direction parallel, and for medium and high carbon steel, the folding surface oxidation decarbonization phenomenon. The folded tail is generally rounded, and the crack is usually sharp. With the crack forging after heating, the crack near the serious oxidation decarbonization, cooling cracks is no such phenomenon. Cracks caused by shrinkage are usually coarse and irregular. Cracks caused by cold correction and cold trimming are trapped in the crack around the crack.

  Usually forging the heat treatment process generally includes heating, heat preservation, cooling the three processes, sometimes only heating and cooling the two processes. These processes are interlinked and irreversible. Forging the entire production process can be carried out in the corresponding heat treatment to improve the performance of metal materials. The heat treatment of the forging as an intermediate step in the manufacturing process can improve certain processing properties (such as forging, machinability, etc.) of the forgings; if used as a final operation, it can impart sufficient mechanical, physical and chemical properties such as metal and alloy , To ensure that the forging products meet the requirements of the quality requirements. Thermal treatment is more effective than mechanical processing and other treatments in terms of the depth and diversity of changes in the structure of forgings. Heat treatment can also be combined with chemical treatment, deformation processing and magnetic field, etc., to further improve the performance of metal materials.