This specification outlines the criteria for hot rolled steel flat sections used in manufacturing laminated springs for railway rolling stock. Steel flats meeting this Indian Standard can be produced from steel ingots, billets, and blooms conforming to IS 8052:1990.

The steel must conform to one of the four specified grades outlined in the standard. IS 8910:1978 lays down the general material supply requirements. Steel production must utilize any steel-making process excluding the Bessemer process, followed by either secondary refining or secondary vacuum melting.

For each specific size of the finished steel product, the size of the ingot, billet, or continuous cast billet must be such that a minimum reduction ratio of 16:1 is maintained from the minimum cross-sectional area of the ingot, billet, or continuous cast billet to the maximum cross-sectional area of the product. However, alternative reduction ratios may be established through mutual agreement between the purchaser and the manufacturer.

The hot-rolled material should be devoid of detrimental defects like seams, folds, laps, cracks, deep pits, grooves, excessive scaling, and other issues that could lead to cracking during hardening or affect its functionality. The surface should exhibit a reasonably smooth texture without any distortion, twists, or kinks.

TESTS

The subsequent test must be conducted for Laminated Springs for Railway Rolling Stock.

• Chemical composition

• Decarburization

• Inclusion rating

• Freedom from defects

• Rolling tolerances

• Cambering test

MARKING:

Marking and packaging procedures must comply with Indian standards. Every flat should bear the manufacturer's name or trademark, grade, and a cast number or any other identification mark enabling traceability to its origin. Additionally, the standard mark (ISI Mark) may be applied to the material.

Manufacturers are required to secure a BIS license from the Bureau of Indian Standards in order to utilize the standard mark (ISI Mark). The Bureau issues licenses following a thorough evaluation of manufacturing infrastructure, production processes, and quality control and testing capabilities conducted during an on-site visit to the manufacturing premises.

PROCESS FOR BIS ISI MARK CERTIFICATION