Hammer crusher is the cement, ceramics, crushing machinery widely used in mines and electric power industries,

Hammer crusher is the cement, ceramics, crushing machinery widely used in mines and electric power industries, the head is the main wear parts, subjected to erosion, long time use of high manganese steel. But because some of the material is not strong crushing impact, high manganese steel with some processing hardening properties can not be fully able to play. So the high manganese steel hammer show wear quickly, using the weakness of short life. In recent years, China's metallurgical casting workers according to the working condition of the use of the hammer, the hammer forward should be met: (1) the right to wear resistance hardness of materials; (2) has certain toughness and resistance to fatigue spalling and prevent crack broken, that is, good strength and toughness. Based on the above understanding, in recent years China Metallurgical Research and development workers a lot of hammer a new wear-resistant cast steel and cast iron materials and composite casting process, in the actual. With these, hammer showed high performance using manganese steel hammer excellent.

Low alloy steel with good strength and toughness, by adjusting the composition and heat treatment process, can be in a wide range of control of hardness and toughness in the reasonable matching, therefore in recent years the development and developed a variety of Multielement Low alloy wear-resistant steel, through on the hammer application received better effect. If according to the organizational division of a new type of wear resistant low alloy steel mainly includes three categories, namely martensite, Austenite Bainite body and Bayesian and Markov body tissue.

Martensite of low alloy wear resistant steel is the most widely used, table 1 for the composition and property of several new low alloy martensitic steel hammer. Martensite of low alloy wear resistant steel is mainly by Cr, Ni and Mo alloying elements, and then through the low temperature quenching and tempering heat treatment, tempering martensite, due to the low alloy martensitic steel in the presence of high dislocation lath martensite body can better abrasion resistance crack growth. Therefore, the material has excellent mechanical properties and wear resistance.

The key is to obtain the Austenite Bainite organization is strongly inhibited in the process of carbide bainite transformation in the silicon, the carbide bainite; manganese increases the hardenability and cross-section uniformity, is to ensure that the main elements of cast self hardening, and also can be combined with silicon, improve casting state of material strength, hardness, impact toughness and keep it high, the bainite formation is a thin strip, the austenite film shape. Choosing proper chemical composition is an important aspect of Austenite Bainite organization. Such as the chemical composition of C:0. 3 ~ 0.5, Si: 2 ~ 3.2, Mn: 1.5 3, Cr: 0.5 ~ 1.5, 0 ~ 1.5: Mo, Ti, B, trace V, RE, can be directly obtained as cast Austenite Bainite Austenite Bainite. Hammer production, industrial experiment life is 2 times of high manganese steel.

Bainite martensite dual phase composite tissue can be obtained through a variety of methods can be used to join. One is obtained by normalizing guimeng, such as chemical composition: C:0. 43, Si: 1.3, Mn: 1.2, Cr: 1.8, Mo: 0.25, B, RE a little later, through the interrupt normalizing; another method is obtained by adding titanium and boron modification and proper heat treatment by the chemical components, such as chemical composition: C: 0.3 ~ 0.45, 0.8 ~ 1.8, Si: Mn: 1 ~ 1.8, 0.8 ~ 1.8 Mo/, Cr: Cu: 0.1 ~ 0.5 Ti/, B: 0.001 ~ 0.003, Re: 0.02 ~ 0 late 6 by Rz - Si - Ca - Ti - B compound modifier is used for modification and quenching + tempering heat treatment, can obtain bainite martensite composite tissue; third kinds of technology by using cheap Si, Mn alloying by Controlled cooling to obtain. Its chemical composition: C: 0. 35 to 0. 70, Si: 1. 0 ~ 2. 5 Mn 2. 0 ~ 4. 0. Then through the use of controlled cooling technology, casting 900 DEG C after austenitizing using an injection (cooling rate) so that the workpiece in the cooling process, avoid pearlite area, rapid cooling to the bainite transformation zone, termination of spray cooling, then the corresponding heat preservation measures, by using the residual heat of casting, to create a similar isothermal quenching of external conditions, to complete the bainite transformation. Hammer of bainite martensite wear-resistant steel production using life of high manganese steel hammer increase 1 times above.

Smelting workers of our country in recent years by adjusting the content of manganese developed new manganese wear-resistant cast steel, chemical composition: C: 0. 9 to 1. 1 Mn 6. 0 to 9. 0, Cr: 1. 0 to 1. 2, Si: 0.5 ~ 0. 8, in addition to join the right amount of trace elements can obtain austenite and martensite + Qu the as cast microstructure of bainite + carbide, single austenite or austenite + granular carbides was obtained after water toughening treatment, properties for the 200 ~ 215 Hb, AK is equal to or larger than 50 J / cm2. Cast state manganese steel hammer life of high manganese steel increased 60%.

On the basis of common high manganese steel, by adopting diversified processing such as adding a certain amount of chromium, molybdenum and vanadium, titanium alloy elements, its initial hardness and yield strength are greatly improved at the same time, still maintain a high toughness, super high manganese steel components such as table 2, mechanical performance is: 230 ~ 320HB, sigma S = 420 to 480 MPa, sigma B = 710 ~ 795 MPa, AK = 100 to 150 J / cm2. Benxi Iron and steel for high impact and high stress under the adverse conditions of 100 kg level of big hammer, the wear resistance is common high manganese steel is 2 ~ 3 times.

High carbon manganese steel is through enhanced high manganese steel with Cr, with the production of hammer in the iron ore is broken, service life is increased by 50%. Compared with common high manganese steel also with manganese content is 17% to 19% of super high manganese steel is used, while increasing the Cr, Mo and improve the yield strength and initial hardness etc. performance, in the actual production has also been a good effect.

Is applied to industrial strength with matrix containing high carbon chromium nickel molybdenum alloy steel chemical composition is shown in Table 3, a higher carbon content, in order to obtain high hardness and a certain number of carbide hard phase, to resist hard materials gouging abrasive wear; and chromium, nickel, molybdenum and other alloy elements added, greatly improve the hardenability of the hammer in the empty cold conditions can be quenched into martensite. Nickel was added to make the steel toughness is further improved, titanium and rare earth addition can refine the grain, grain boundary purification, improve steel. The hardness of the material 52 to 58 HRC, AK = 14 to 20 J / cm2, in cement plant site, the wear resistance of high manganese steel of 2. 8 to 4. 7 times.