Hastelloy C, NS 3303 Chemical composition, structure and performance characteristics

The chemical composition of this alloy is shown in Table 8-7. According to the ternary phase diagram of Ni-Cr-Mo, it is known that only a uniform single-phase austenite structure is obtained at 1150 ゚C, and it can be kept in a single phase only by solution treatment at a temperature of >11501 and rapid cooling. Sterile tissue. When treated below this temperature or slowly cooled, the alloy will consist of the y + P phase. The sensitization of 700~1050 ゚C, the structure of the alloy is y+ u+ carbide, and these precipitation phases are harmful to the corrosion resistance and plasticity of the alloy.

The alloy is wet chlorine, various oxidizing chlorides (ferric chloride, copper chloride, mercuric chloride, etc.), hydrochloride solutions (calcium chloride, magnesium chloride, lead chloride, etc.), sulfuric acid and oxidizing salts. It has excellent corrosion resistance in various concentrations of organic acids in mixtures, sulfurous acid and boiling temperature, and has excellent pitting and crevice corrosion resistance in chloride solutions and seawater. It is the only corrosion resistant metal material in wet chlorine. The deficiency of this alloy is that there is intergranular corrosion in the sensitized state.

8.3. 1.2 Mechanical properties
The transient mechanical properties of 0Crl6Ni60Mol6W4 alloy at room temperature and high temperature are shown in Table 8-8.

Table 8*8 Instantaneous mechanical properties of 0Crl6Ni60Mol6W4 alloy at room temperature and high temperature