Casting heat treatment control of cast steel cable clamp

G10mnmov6-3 low alloy cast steel cable clamp is heat treated by quenching + tempering. The heat treatment process is shown in the figure.

The mass ratio of quenched cast steel cable clamp casting to quenchant is 1: (6 ~ 8). During quenching, the temperature of Quenchant should be controlled below 40 ℃, and the cast steel cable clamp casting should keep moving in the quenchant. 175kW desktop resistance furnace is used for quenching, and 2.5m is used × 4m × 3M quenching pool, using special quenching liquid. The heating rate is determined to be 80 ~ 130 ℃ / h. After the temperature rises to 965 ± 15 ℃, it shall be kept warm for 8h, and then it shall be discharged from the furnace and quickly cooled to 300 ℃.

The internal structure of g10mnmov6-3 low alloy cast steel cable clamp after quenching is low-carbon martensite + a small amount of residual austenite. Due to the internal stress in the structure of cast steel cable clamp after quenching, it is easy to cause deformation or cracking. Therefore, it is generally necessary to temper at high temperature to change its structure into tempered sorbite (granular pearlite). After several tempering tests on the first piece of cast steel cable clamp, it is finally determined that the heating rate is about 100 ℃ / h, the temperature rises to 650 ± 10 ℃ for 8h, and then stop heating and natural cooling in the furnace. The heat treatment (quenching + tempering) of large test blocks poured in the same furnace shall be carried out together with the cable clamp. It can be seen from the mechanical properties (see table) that the heat treatment process is reasonable.