4J58 Overview

4J58 is an alloy with a specific coefficient of expansion within the temperature range from room temperature to 600°C. At ambient temperature, its coefficient of expansion is essentially consistent with that of steel and cast iron, and it possesses good machinability. It demonstrates excellent dimensional stability during long-term use and has certain corrosion resistance.

4J58 Heat Treatment System

As specified by the standard, the test sample for coefficient of expansion performance is heated to 900°C ± 20°C in hydrogen or vacuum, held for 1 hour, and then cooled to below 200°C at a rate not exceeding 5°C/min before being removed from the furnace.

4J58 Application Overview and Special Requirements

This alloy exhibits stable performance and is primarily used to manufacture precision linear scales (standard rulers) for transmitting standard lengths at room temperature (20°C), as well as engraved scales fixed on the bed of coordinate boring machines. Special attention should be paid to the content of carbon and other impurities during production and acceptance, as they are one of the causes of dimensional instability. Additionally, internal stresses induced by subsequent processes should be minimized as much as possible, and the production cycle should be appropriately extended for natural aging.

Forming Performance

The alloy has good hot and cold working properties.

Welding Performance

The alloy has good welding properties.

Component Heat Treatment Process

During planing and grinding processes, components should undergo multiple repeated heat treatments to achieve uniform microstructure, eliminate internal stresses, and ensure dimensional stability during long-term use.

Surface Treatment Process

Surface treatment can include sandblasting, polishing, and pickling.

Machining and Grinding Performance

The alloy has good machining, grinding, polishing, and engraving properties.

The above is an introduction to the 4J58 iron-nickel controlled expansion alloy material.

Various specifications of plates, bars, strips, wires, discs, ring blanks, and ring forgings are available. Bars are supplied in as-forged or as-rolled condition, with surfaces ground or turned; discs and ring blanks are supplied in as-forged condition; rings are supplied in solution-treated condition; plates are supplied after solution treatment, alkali pickling, straightening, and edge trimming; strips are delivered after cold rolling, solution treatment, and descaling; wires are supplied in solution-pickled coil or straight lengths, or in solution-treated straight fine-ground condition.