Quality Control at LNM Auto

Not be left Behind in show casing how we manage Quality Control we take this opportunity to introduce one of our Quality Control machines for testing hardness-

LNM Auto has installed MIRO HARDNESS TESTER model of M/S CHROMA SYSTEMS. The tester is used for micro loads ranging from 100 gms. to 3000 gms. for estimation of VICKERS HARDNESS using a diamond pyramid indenter. The tester is accomplished by a software computer interfaced for auto measurement and reporting.

The operation involves keeping the polished specimen on the table of the tester and the numbers of impressions by indenter are programmed at fixed interval of the distance from surface. The impressions are measured for two diagonals of the pyramid automatically for Vickers’s hardness. The software gives the graph of Hardness v/s Distance. The effective case depth is automatically calculated by feeding the cut off value in the software.

Major applications involves Effective Core Depth (ECD) measurement of case carburised parts, Decarb & Partial decarb values, hardness of very small and thin parts.

Here is a Typical Report format that we share with our customers lnm-quality-controlmicrohardnessanalysis.pdf

The Beauty for your eyes :=)

Forging

Beginning today I will be sharing the some of the manufacturing processes with the readers of our blog. It is so important to know how we are able to produce with precision what we do for our consumers. Today I will talk about Forging process.

Forging is the working of metal by plastic deformation The processes of raising, sinking, rolling, swaging, drawing and upsetting are essentially forging operations although they are not commonly so called because of the special techniques and tooling they require.

Forging results in metal that is stronger than cast or machined metal parts. This is because during forging the metal’s grain flow changes into the shape of the part, making it stronger. Some modern parts require a specific grain flow to ensure the strength and reliability of the part.

Many metals are forged cold, but iron and its alloys are almost always forged hot. This is for two reasons: first, if work hardening were allowed to progress, hard materials such as iron and steel would become extremely difficult to work with; secondly, most steel alloys can be hardened by heat treatments, such as by the formation of martensite, rather than cold forging. Alloys that are amenable to precipitation hardening, such as most structural alloys of aluminium and titanium, can also be forged hot, then made strong once they achieve their final shape. Other materials must be strengthened by the forging process itself.

Forging was done historically by a smith using hammer and anvil, and though the use of water power in the production and working of iron dates to the 12th century CE, the hammer and anvil are not obsolete. The smithy has evolved over centuries to the forge shop with engineered processes, production equipment, tooling, raw materials and products to meet the demands of modern industry.

In modern times, industrial forging is done either with presses or with hammers powered by compressed air, electricity, hydraulics or steam. These hammers are large, having reciprocating weights in the thousands of pounds. Smaller power hammers, 500 pounds or less reciprocating weight, and hydraulic presses are common in art smithies as well. Steam hammers are becoming obsolete.

In industry a distinction is made between open- and closed-die forging. In open-die work the metal is free to move except where contacted by the hammer, anvil, or other (often hand-held) tooling. In closed-die work the material is placed in a die resembling a mold, which it is forced to fill by the application of pressure. Many common objects, like wrenches and crankshafts, are produced by closed-die forging, which is well suited to mass production. Open-die forging lends itself to short runs and is appropriate for art smithing and custom work.

Closed-die forging is more expensive for mass production than is casting, but produces a much stronger part, and is used for tools, high strength machine parts and the like. Forgings are commonly used in automotive applications, where high strength is demanded, with a constraint on the mass of the part (high strength-to-mass ratio). Forged parts are more suitable for mass production. The process of forging a part becomes cheaper with higher volumes. For these reasons forgings are used in the automotive industry, usually after some machining. One particular variant, drop forging, is often used to mass produce flat wrenches and other household tools.

LNM is into these two types of forging processes.

Hydraulic press forge

In hydraulic press forging the work piece is pressed between the two die halves with gradually increasing force, over a period of a few seconds. The quality of the pieces is better than drop forging as there is more control over metal flow, but takes longer and requires more energy. It also makes the same shape continuously

Hot forging

Forging is the hammering or forming of hot or cold metal into a certain shape. When the hammering and forming is done by hand it is called hand forging and when it is done by machine it is called drop forging. The forging process starts after having brought the steel to the correct workable temperature between 900°C and 1100°. It allows us, through a process of reduction (for crushing), to get the most various shapes