Cast steel for bearing parts in mechanical lifting system and its making process

Abstract

The present invention relates to one kind of cast steel for bearing parts in mechanical lifting system and its making process. The cast steel of Cr-Ni-Mo line consists of C 0.15-0.30 wt%, Mn 0.60-1.10 wt%, Si 0.3-0.8 wt%, Ni 0.4-1.1 wt%, Cr 0.4-1.1 wt%, Mo 0.15-0.40 wt%, S less than 0.025 wt%, P less than 0.025 wt%, and residual elements including Cu, W and V less than 0.60 wt%. The making process of the cast steel includes the following technological steps: making steel in MF furnace or electric arc furnace; casting in sand mold with equivalent circular kiel test rod; normalizing, quenching and tempering of both cast part and test rod in the same furnace; and non-destructive detection of the cast part.

Description

technical field [0001] The invention relates to cast steel for bearing parts of a lifting system of mechanical equipment and a manufacturing method thereof, and is particularly suitable for cast steel materials for bearing parts of a lifting system of petroleum machinery and equipment. Background technique [0002] At present, the key load-bearing parts in the lifting system of mechanical equipment, especially the load-bearing parts of petroleum machinery lifting equipment such as hook bodies, hook cylinders, lifting rings, elevators, etc., require high comprehensive mechanical properties. Oil workover main lifting equipment SY / T5208-2000 standard (issued by Petroleum Industry Press, published in December 2001), elevator SY / T5041-92 standard (issued by Petroleum Industry Press, published in September 1992) and other instructions are currently used The main materials for manufacturing casting hook bodies, hook cylinders, elevators and rings are ZG34Cr2Ni2Mo and ZG35CrMo. "Ca...

AI Technical Summary

Problems solved by technology

[0004] The problem to be solved in the present invention is to propose a new high-strength and high-toughness cast steel material and its manufacturing method for the bearing parts of the lifting system of mechanical equipment. The cast steel material can meet the low-temperature impact performance Akv proposed by the American API Spec 8C specification for castings. ≥42J (-20°C) requirements, and solve the problems of low toughness and high cost of cast steel materials currently in use