What's heat treatment process of high chromium casting iron？

Heat treatment process of high chromium casting iron

Chemical composition: c2.05, si1.40, mn0.78, cr26.03, ni0.81, mo0.35 

The common heat treatment process of high chromium cast iron is heating to 950 ~ 1000 ℃, then tempering at 200 ~ 260 ℃ after heat preservation and air cooling quenching.  

The impact toughness and wear resistance can be significantly improved by spheroidizing at 1140 ~ 1180 ℃ for 16 h and air cooling. High temperature spheroidizing treatment can make all carbides become spherical, which can eliminate or reduce the effect of large and continuous network carbides on the matrix. 

The carbide after spheroidizing is supported by more uniform matrix, especially by a certain amount of austenite. If the holding time is reduced properly, the effect can also be achieved for thin section parts. The disadvantage of this process is that it consumes more heat energy. 

How about heating to 1050 ℃ and tempering at 550 ℃ after holding air quenching? To control the heating speed, it is better to hold at 650 750 850 ℃ for a certain time. I've done it before, just normalize it. The hardness can reach 61-65hrc. The mature process is: softening and annealing after casting, easy to process, air cooling quenching and low temperature stress relief tempering after processing. 

Wear resistant white cast iron series

The series includes high chromium cast iron, medium chromium cast iron, low chromium cast iron, nickel hard cast iron and high chromium cast steel. Overall advantages: high hardness, good wear resistance. Disadvantages: lack of toughness.

1）The high chromium cast iron (cr14-30%) has the best wear resistance and the widest application range, such as lining plate, ball and segment of medium and small mill, hammer head and plate hammer of small crusher, vertical mill roller and plate, etc. After the roller press is equipped in front of the large mill, the high chromium cast iron can develop its advantages and avoid its disadvantages, give full play to its excellent wear resistance, and the service life of the lining plate can reach more than 8 years.

2）The hardness and toughness of low chromium cast iron (cr1.5-3%) are much lower than that of high chromium cast iron. It is mainly used for ball, segment and fine grinding bin liner. Its advantages are low production cost, but its disadvantages are narrow application range, general comprehensive performance and anti-wear index. Medium chromium cast iron (cr8-14%) is only used for ball casting. Reducing the chromium content can not only reduce the production cost, but also meet the crushing rate index of football. It is still called high chromium ball in the market.

3）The hardness is generally required to be HRC58-62, which is mostly used for wear-resistant parts such as slurry pump parts. We are here high chromium production base, generally provide cr24, Cr26, Cr28, cr15mo3, the price is not cheap. The price includes intermediate softening annealing and quenching and tempering after finishing. 

The material of the building owner should be Cr26, which is used as high chromium grinding ball. CR% = 10.2 ~ 10.5%, C% = 2.2 ~ 2.7%, Si and s are below double zero, and the hardness is required to be HRC > 58. Now we use quenching liquid for quenching, and the quenching process parameters are: 650 ℃ for 2 hours, 960 ℃ for 3.5 hours, and 380 ~ 400 ℃ for 4 ~ 6 hours. The ball size is from 40 to 80. The process is 1050 quenching + 250 ~ 350 tempering.

Application of high chromium alloy casting: 

Mainly used for crusher hammer, plate hammer, impact plate, VSI crusher spare parts

Hyton is a famous foundry of high manganese and high chrome castings for more than 16 years. Our main products are mantle,concave,jaw plate, blow bar,hammers and vsi crusher wear parts etc. About impact crusher and hammer crusher parts, hyton focus on being help on blow bar, breaker plate, hammers,VSI crusher parts.