Strength and toughness treatment of heavy-duty casters by industrial caster manufacturers

Before forging universal wheel materials, industrial caster manufacturers typically use higher heating and holding temperatures to completely dissolve the Nb carbides and carbonitrides formed during continuous casting of molten steel. For 0.5%C and 0.06%Nb forged steel, the Nb compound will not completely dissolve at the conventional heating temperature of 1250℃.

When the carbon content in the steel is lower, the Nb content in the solid solution is higher at the same temperature.

The solubility of microalloying elements in steel is not only affected by carbon content, but also by nitrogen content, but has little effect on the solubility of microalloying elements in universal wheels. In addition, in the forged steel, under equilibrium conditions, almost all the precipitation of the universal wheel occurs in the austenite temperature range, while the precipitation of the low carbon content HSLA steel (high strength low alloy steel) occurs in a large amount at 900 ° C In the following ferrite temperature region, the size of the precipitates in ferrite is small, usually less than 10nm, which is beneficial for improving the strength of steel by its precipitation strengthening effect, while the size of the precipitates formed in austenite is relatively coarse. Some (20-50nm) are beneficial for grain size control. The role of microalloying elements in the universal wheel is to refine the grains, traditionally. This improves the strength and toughness of the steel while relying on the precipitation of microalloying elements to further increase the strength.

Commonly used microalloying elements in steel are TiNbV and Al. The role in steel is usually to improve seamlessness by precipitation reinforcement. The role of the microalloying elements in the universal wheel is to refine the grains to improve strength and toughness, while relying on the precipitation of microalloying elements to further improve the strength.

The commonly used microalloying elements in steel are TiNbV and Al. The role of steel is generally to improve the strength of the universal wheel through precipitation strengthening, and the contribution of solid solution strengthening to the strength of steel is much lower, so these elements are used in industrial production. Sufficient consideration should be given to the solid solubility in the austenitizing process.

Compared with flat products with low carbon content, medium carbon special steel usually contains high nitrogen content, so large-sized TiN is inevitably formed in the universal wheel. Due to the small solubility product of TiN, the primary precipitates produced by these large-sized TiN precipitates during the solidification of steel and steel are very detrimental to the fatigue properties and toughness of the material, so the upper limit of microalloying elements should be limited.

For steels containing CrMo, when the Nb content is 0.09% and the carbon content exceeds 0.6%, there will still be a primary precipitate even under equilibrium conditions.