SU1168627A1 - Composition for boronizing and aluminizing steel articles - Google Patents

Abstract

COMPOSITION FOR BOROALITHM OF STEEL DETAILS, containing boron carbide, an aluminum-containing substance. Aluminum chloride and aluminum oxide, characterized in that, in order to improve the hardness and heat resistance of the workpieces, it additionally contains ferrovanadium, and as an aluminum-containing substance - aluminum powder in the following ratio of components, wt.%: Boron carbide 30-35 Aluminum powder 6 -10 aluminum chloride 1-3 ferrovanadium 4-6 alumina rest

Description

The invention relates to metallurgy, in particular to the chemical-heat treatment of steel products, namely, thermal diffusion saturation of chromium-Nickel steels and alloys with boron and aluminum, and can be used to protect parts from high-temperature gas corrosion and erosion. The purpose of the invention is to increase the hardness and heat resistance of the workpiece. Entering into the composition of ferrovanadium, due to the fact that ferrovanadium, taken within the specified limits, does not affect the kinetics of the formation of the diffusion layer, but gives it plasticity and increases the surface microhardness. This has a significant effect on the erosion resistance of the coating. The use of aluminum powder improves the surface quality after saturation. Saturation from the proposed composition allows to obtain high-quality coatings of high microhardness and high heat and erosion properties. Example: The process of boiling is carried out on samples of steel X22H18 at 900-IIOO C in a fusible container. The duration of the saturation depends on the desired Depth of the bed and is 1-5 hours. In the table. Figure 1 shows the proposed boronalyzing compositions. Table 2 shows the microhardness and heat resistance of coatings formed from these compositions. Heat resistance tests were carried out on samples of steel X23H18, saturated at 950 ° C and a duration of 2.5 hours. The heat resistance of the coating was evaluated by the weight of the coated samples after the test. The microhardness of the coatings is measured after saturation. As can be seen from the data given in Table 2, the boron catalytic analysis from the proposed composition allows to obtain coatings with microhardness 2-2.5 times and heat resistance 2.5-3 times higher than the coatings obtained from the proposed composition. The higher microhardness of the coating formed from the proposed composition allows us to speak of a higher erosion resistance of this coating. Thus, the use of the proposed composition allows to simultaneously increase the hardness and heat resistance of the resulting coatings.

30 32 35 32 38 28

ten

6

eight

four

12

Table 1

53

3

53

one

52

2

52

2

55.5

0.5

48

4 Lime chloride composition contains boron carbide 42-, borax 8; aluminum 25; aluminum 1.5; alumina 23.5.

Claims (1)

COMPOSITION FOR BOROALITIZING STEEL PARTS, containing boron carbide, aluminum-containing substance, aluminum chloride and aluminum oxide, characterized in that, in order to increase the hardness and heat resistance of the machined parts, it additionally contains ferrovanadium, and aluminum powder as an aluminum-containing substance in the following ratio of components , May.%: Boron carbide 30-35 Aluminum powder 6-10 Aluminum chloride 1-3 Ferrovanadium 4-6 Alumina Rest I 1,168,627 2