Research On Precipitation Controlling And Abrasive Mechanism Of A Kind Of Ti Micro-alloy Wear-Resistant Steel

High-strength wear-resistant steel is widely used in mining machinery, engineering machinery, building materials, transportation and other aspects. As its core production process has long been monopolized by foreign minority, our country can only produce low-end wear plate products such as NM360and NM400. In recent years, through introducing the second phase into martensite matrix to further improve the comprehensive performance of high strength martensitic wear-resistant steel is a hotspot. In addition, due to widespread use of domestic wealth of alloying elements and avoid the use of rare and precious metals, production costs are reduced. Combining with NM500grade martensitic wear-resistant steel at home and abroad, a certain amount of microalloy element Titanium was added on Cr-Mo component system and through controlling the hot-rolled and heat treatment parameters, the precipitation of microalloy element Titanium in martensite was promoted to wear resistance, finally new super-high strength Ti micro-alloy wear-resistant steel was reached and developed. The main work and obtained achievements are as follows:(1) Using thermal simulation test machine, the experimental steel double pass compression deformation, then cooled by the cooling rate of10℃/s to600℃,650℃,700℃and were incubated in0s,5s,10s,100s,300s,500s and1000s,then testing the various experimental conditions tested steel microstructure and properties. Experimental steel containing V element was obtained lath martensite steel and has a higher hardness. The experimental steels contain V the holding time increases gradually with the ferrite phase appears, and can achieve low hardness value.(2) Two-stage controlled rolling and four kinds of cooling mode were designed.Cooling to600～650℃by the cooling rare of10℃, respectively, in the furnace insulation10s and60min after direct quenching to room temperature, testing the experimental system under different rolling steel microstructure and properties. V containing experimental steel are significantly higher than excluding V experimental steel, and experimental steels containing V has a higher yield strength, tensile strength, hardness and toughness, but lower elongation than excluding V Experimental steel, Therefore, it has lower plastic.(3) Impact at low stress abrasive wear conditions, we study the wear behavior of the experimental steel. The results show that by the double-pass rolling and10℃/s cooling to600～650℃, and then incubated in the furnace quenching process after10s, the wear resistance V containing experimental steel to excluding V experimental steel is1.23times. In the oven for60min after the hardening process, the wear resistance of V containing experimental steel is excluding V experimental steel1.04times. When the soaking time is10s, the quantity of precipitations of the A steel is more than the B steel. When the soaking time is60min, the quantity of precipitations of the A steel is more than the B steel too. So some content of V has benefit effect on the boost of the quantity of the precipitations.(4) We study the wear mechanism of the experimental steel by observation of wear morphology. The results show that by the double-pass rolling and10℃/s cooling to600-650℃, and then incubated in the furnace quenching process after10s, the primary wear mechanism of experimental steel is micro-ploughing and micro-cutting. In the oven for60min after the hardening process, the primary wear mechanism of experimental steel is micro-fatigue and micro-cracking, and combining with micro-plough and micro-cutting.