Bainite structural steel used for high strength fastener

Abstract

The invention discloses a bainite structural steel used for a high strength fastener. The bainite structural steel comprises the following chemical components by weight: 0.04%-0.08% of C, 1.20-1.80% of Mn, 0.60%-0.80% of Si, less than or equal to 0.010% of S, less than or equal to 0.010% of P, 0.06%-0.08% of Nb, 0.15%-0.25% of V, 0.04%-0.06% of Ti, 0.005%-0.010% of N, 0.005%-0.007% of B, less than or equal to 0.035% of Als, and the balance Fe and inevitable impurities.

Description

technical field [0001] The invention relates to the technical field of iron and steel metallurgy, in particular to a bainitic structural steel for high-strength fasteners. Background technique [0002] Fasteners are one of the three basic mechanical components. Cold heading steel wire is the main raw material for making bolts, nuts, screws, rivets and other fasteners. For the production of high-strength fasteners, 40Cr, 35CrMo and other alloy structural steels can be used as materials, and quenched and tempered heat treatment is carried out after deep processing. Its production process: raw material inspection → spheroidizing annealing → pickling → phosphating treatment → primary drawing → annealing → pickling → phosphating treatment → secondary drawing → cold heading → wire rolling → quenching, tempering (quenching and tempering treatment ) → electroplating → product performance inspection. This quenched and tempered fastener production method, on the one hand, requires ...

AI Technical Summary

Problems solved by technology

This quenched and tempered fastener production method, on the one hand, requires the addition of alloying elements to increase the production cost, and on the other hand, due to the need for subsequent heat treatment, it increases energy consumption and reduces productivity.