1. Hardness test The sampling position of the hardness sample of the gray cast iron cylinder block is shown in Figure 1. The hardness test of the cylinder position needs to test the hardness for 3-4 times at equal intervals to test whether the hardness distribution of the cylinder...
1. Metallographic observation The metallographic sample is taken from the gray cast iron cylinder body, cut and sampled with a cutting machine, and the sampling position is shown in the figure. The removed samples are inlaid with epoxy resin, ground on 120, 280, 400 and 500 sandpaper respectively, and...
Figure 1 shows the model and production flow chart of a high-strength gray cast iron engine cylinder block. The main processes include raw material ratio, baking process, molding, core making process, pouring process and post-treatment process: (1) Ingredients; The ingredients are divided into raw materials and auxiliary materials. According...
Gray cast iron is mainly composed of matrix structure and graphite, and others include eutectic, carbide and cementite eutectic. Its microstructure determines its performance. When observing its metallographic structure, it is mainly analyzed and studied from the aspects of flake graphite, metal matrix and eutectic at grain boundary. The...
Cast iron generally refers to multi-component iron carbon alloy with C content of 2.0% (wt%, the same below) W. Generally, the C content of industrial cast iron is 2.5-3.5%. C exists in gray cast iron in the form of W graphite and a small amount of W PA C....
Gray cast iron is the most widely used cast iron at present. It is named for its gray section color. In addition to the highest content of Fe, there are also C, Si, Mn, P, s and other elements in gray cast iron; Among them, C, Si and Mn...
The series of experiments were carried out on the filling process of lost foam casting of gray cast iron by using the computer data acquisition system, and the following conclusions were obtained: The orthogonal test results show that the relative importance of the technological factors affecting the filling rate...
Many observations and experiments have shown that the liquid metal is filled radially forward in the filling process of lost foam casting. In the process of lost foam casting filling, under the thermal radiation of molten metal, before the molten metal contacts the pattern, the pattern begins to vaporize,...
The filling process of lost foam casting has a decisive influence on the quality of castings. Due to the existence of foam pattern, gasification decomposition and the interaction between decomposition products and molten metal, the filling process of molten metal and the generation and control of casting defects are...
The changing trend of the influence of pouring temperature on the average mold filling speed of molten metal in lost foam casting shows that the thermal decomposition characteristics of pattern materials significantly affect the mold filling speed of molten metal. Generally speaking, the gas generation rate depends on the...