AISI 4140 Alloy Plate

DESCRIPTION

Modified alloy plate is a medium carbon, medium alloy steel. This plate has a hardness, strength and toughness that cannot be achieved in mild plate steel. This material finds application where AISI 6150 or similar alloys are acceptable, but not available in large sections. In the annealed condition, modified alloy plate steel machines as well as comparable materials with comparable structures. The one percent chromium alloy addition imparts a greater degree of strength and toughness than is possible with carbon plate steel of the same carbon content.

The alloy content allows the steel to be hardened fully in oil thereby resulting in a finished product having a minimum of movement and distortion.

TYPICAL ANALYSIS

CARBON ……………0.40 SULPHUR ………………..0.04

MANGANESE ……...0.90 MOLYBDENUM ………...0.21

CHROMIUM ……….0.90 PHOSPHOROUS ………..0.04

SILICON …………….0.25

HEAT TREATMENT

May be hardened safely by any of the conventional method of treatment: direct heating and quenching, flame hardening, induction hardening, and in some cases, carburizing and hardening if the mass of section or if the design permits.

The physical and thermal properties compare favorably to those of similar steels. In flame hardening, the expected hardness range is Rockwell C 58-60 regardless of section size, since only the immediate surface is affected by this process of hardening.