Standard

 

MCA 228 – Characteristics of Metals/Heat Treatment II

Course Description

Emphasizes selection of proper tool steel for specific tooling operations, and proper heat treating procedure of tool steels. Topics include: effects of alloy components in tool steel, identification of tool steel alloys, identification of tool steel by classification, and correct heat treatment procedures.

 

Competency Areas

Hours

 

Tool Steel Alloy Components

Class

4

Identification of Alloys

D. Lab

2

Identification of Tool Steels by Classification

P. Lab/O.B.I.

0

Correct Heat Treating Procedures

Credit

5

 

 

 

Prerequisite:

MCH 107

Corequisite:

 

 

Course Guide

 

Competency

After completing this section, the student will:

Hours

Class

D.Lab

P.Lab/

O.B.I.

STEEL ALLOY COMPONENTS

 

 

 

Terminology

Describe alloy, tool steel, carbon steel, high speed steel, eutectic, heat treatment, phase change, alatropic metals, quenching, martinistic, and pearlite.

 

 

 

Structure

Explain the iron - iron- carbide phase diagram.

 

 

 

 

Describe the affect phase changes have on carbon in steel.

 

 

 

 

Explain austenitic properties and the importance of austenite in heat treatment.

 

 

 

 

Diagram and describe the lattice structures found in metals.

 

 

 

Physical properties

Define the terms that pertain to the physical properties of metals (hardness, ducticity, tensile strength, etc.).

 

 

 

 

Describe the testing methods to determine the physical properties of metals.

 

 

 

 

List common alloys of steel and the affect the alloy has on the physical properties of steel.

 

 

 

 

Describe forces on cutting tools and the affect of temperature increases during cutting operations on steel alloys.

 

 

 

IDENTIFICATION OF ALLOYS

 

 

 

Theory

Explain SAE codes for common alloys of steel.

 

 

 

 

Describe the processes and explain why the smelting process would affect the properties of an alloy.

 

 

 

 

Demonstrate a spark test of carbon steels and determine carbon content.

 

 

 

 

Explain how a magnet can help identify alloys of steel.

 

 

 

Application

Identify common steel alloys.

 

 

 

IDENTIFICATION OF TOOL STEEL BY CLASSIFICATION  

 

 

 

 

Explain the ASTM and SAE numbering system for steel.

 

 

 

 

Explain the classification of steel by alloying elements.

 

 

 

 

List by number types of steel alloys used in tool steels with the advantages of each.

 

 

 

HEAT TREATMENT

 

 

 

Terminology

Define the terms used in heat treatment by process and by components of each process (hardening, annealing, etc.).

 

 

 

 

Describe systems for applying heat for heat treatment.

 

 

 

 

Explain quenches, severity, and what the severity is compared to as a standard.

 

 

 

 

Describe the forms that carbon takes during heat treatment and how the different forms affect properties of steel.

 

 

 

 

Describe case hardening, its advantages, disadvantages and processes used to achieve case hardened material.

 

 

 

Application

Perform heat treatment processes of high carbon steel and test the properties before and after treatment.

 

 

 

 

Suggested Resources

 

Books

 

Cain, T. (1984). Hardening, tempering and heat treatment. Tucson, AZ: Aztex.

Heat treating, cleaning and finishing. (1964).

Machining metals handbook. (1989). Materials Park, OH: ASM International.

Ross, R. B. (1977). Handbook of metal treatments and testing. Tucson, AZ: Aztex.

Tool materials for high-speed machining. (1987). Materials Park, OH: ASM International.

Walker, J. R. (1989). Machining fundamentals. South Holland, IL: Goodheart-Willcox.