Micro-alloying high-strength fork steel

Abstract

The present invention discloses a microalloyed high-intensity steel used for pallet porks with a weight percentage of chemical compositions as follows: C 0.28-0.37 percent, Si 0.15-0.45 percent, Mn 1.20-1.60 percent, Cr0.25-0.65 percent, S less than or equal to 0.030 percent, P less than or equal to 0.030 percent, Ti 0.015-0.100 percent, B 0.005-0.0040 percent and the remainder is Fe. The chemical compositions still contains Ni less than or equal to 3.0 percent, V less than or equal to 0.5 percent, Nb less than or equal to 0.5 percent, Cu less than or equal to 0.5 percent and Mo less than or equal to 0.5 percent. The invention adopts the microalloyed B and Ti to improve the hardenability of the material notably, to meet the hardenability requirement of the monolithic quenching of big workpieces and promote the comprehensive mechanical property of the material greatly, so compared with the alloyed Mo steel material of the same hardenability, the precious metal Mo can be saved by 20 percent or more per ton, and the cost of the steel can be reduced by approximately 1000 yuan per ton.

Description

Technical field: [0001] The invention relates to alloy steel in the iron and steel industry, in particular to a micro-alloyed steel for high-strength pallet forks. Background technique: [0002] With the development of modern industry, higher requirements are put forward for the strength, hardenability, low temperature performance, shape, size and dimensional tolerance of steel materials. For some specific steel types, such as special steel for forks, the entire fork needs to be quenched as a whole in the production process of the fork, so there is a high requirement for the hardenability of the material used for the fork. At present, the materials of special steel for domestic forks are mostly 35Cr, 40Cr, 35CrMo and so on. 35Cr, 40Cr and other steels are often quenched and hardened, which affects the overall mechanical properties of the material, while 35CrMo has superior hardenability, but because it uses the rare metal Mo, it is not only costly, but also not conducive to...

AI Technical Summary

Problems solved by technology

35Cr, 40Cr and other steel types are often quenched and hardened, which affects the overall mechanical properties of the material, while 35CrMo has superior hardenability, but because it uses rare metal Mo, it is not only costly, but also not conducive to the long-term development of the national economy.

[0003] As B steel, at present, there are 20MnTiB steel grades in China, but this steel grade is generally used for small-section steel materials to manufacture high-strength fasteners, etc. For the overall large-end high-strength workpiece, the comprehensive performance of this steel material cannot reach manufacturing Overall requirements for forks

Moreover, due to the well-developed dendrites of this steel type, shrinkage cavities are easily formed during the solidification process, so it is basically not used in the current market.