Lost foam casting technology and carburizing defects of bridge bearing

This paper mainly carries out scheme design, simulation analysis and production verification of a kind of bridge bearing steel casting, and selects the casting scheme with better quality. Then through the orthogonal test of three main process parameters, the optimal combination of process parameters is determined. On this basis, through the production and experimental research of two kinds of foam materials, EPS and STMMA, the distribution law of carbon defects under different foams and the degree of influence on the chemical composition and mechanical properties of steel castings were compared, so as to determine a high quality and low cost production technology scheme.

The main research contents are as follows:

(1) In this paper, the structure analysis, process parameters selection and two pouring schemes (horizontal pouring and vertical pouring) design are carried out for a representative steel steel bearing in bridge bearing.

(2) Using Creo three three three diagram software, according to two pouring schemes, the three three entity model of steel steel bearing and pouring riser is built and assembled.

(3) Pro cast simulation software was used to mesh the two casting schemes, and the parameters were set and simulated.

(4) The simulation results of the two casting schemes were compared and analyzed, and combined with the production verification of the experimental parts, the better pouring scheme was determined.

(5) The orthogonal test was carried out on the three main process factors (pouring temperature, negative pressure degree and pattern density) which affected the casting quality, and the optimal combination scheme of process parameters was determined. On this basis, the second optimization is carried out to improve the product quality and process yield.

(6) production verification was carried out according to the final optimized process plan. The chemical composition and mechanical properties of low carbon steel castings produced by two kinds of foam materials EPS and STMMA were compared and analyzed, and the distribution rule of carburizing defects and the influence of carbon deficiency defects on the quality of steel castings were studied.