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Fig. 1. Training methods |
A number of companies and organizations offer a variety of training programs to ensure that heat-treat operators, supervisors, maintenance personnel, quality people, engineers, managers and just about everyone who is involved in heat treating knows and understands the subject. Companies want their employees to know as much as possible about what their company does, what products they produce and how these products are manufactured. The heat-treat process is no exception.
Most training programs are, or should be, designed to meet the requirements of a formal structured program such as SAE-ARP-1962 (Training and Approval of Heat-Treating Personnel). This document calls out both classroom instruction and OJT (on-the-job training) for heat treaters. However, a key element to the success of any program is the inclusion of a “hands-on” training portion by someone skilled in the type of processes and equipment being run. Let’s learn more.
How We Learn
It is important to recognize that learning continues over one’s lifetime and is not just a one-time event. Different people learn in different ways: through books, in formal (classroom) settings, by word-of-mouth, by reading trade journals (such as Industrial Heating!), by watching others, from the Internet, by participating in training programs, by trial and error and by being shown how (and, hopefully, why) something works. This last method is what hands-on training is all about. This type of training has been found to be highly effective in shortening the learning curve and breaking bad habits. In addition, the recipients gain practical experience on the furnace systems relevant to them.
The Value of Training
The payback for training is tremendous including such benefits as:
- Immediate reinforcement of newly acquired knowledge
- Linking of theory and practice in a natural way
- Deeper understanding of the intricacies of heat treating
- A more satisfied and responsible heat-treat operator
- Individuals who see their company investing in them for the future
- A more confident management team due to the investment in personnel training
- Confident employees more willing to take on new responsibilities and offer positive suggestions for continuous improvement
- Customers who gain confidence in the company’s ability to provide a quality product or a solid professional service
- The satisfaction and, more importantly, the motivation gained by knowing that things are done correctly
The Need for Continual ReinforcementIt is essential that BOTH initial and (annual) reinforcement training be done. Too often companies train individuals and feel their obligation is complete. In education circles it is well known that a student must be exposed to the same subject matter (in slightly different forms) a minimum of four to six times before they gain a thorough understanding of the subject. An instructor knows that they must present (teach) a subject at least three times themselves before he or she fully understands it! So how can a student only be exposed once? New hires must also go through both basic and advanced training in order to be successful.
Why In-House Training?
Valid and compelling arguments can be made for online training (or so-called distance learning), home-study courses and off-site training in a formal classroom environment. Each of these methods is necessary but should not take the place of in-house education that includes a hands-on element. Home-field advantage should not be underestimated. Individuals to be trained need to see that what they have learned can help them right away, on a day-in and day-out basis. Too often more formalized training materials sit on shelves, sadly never to be looked at again.
In most organizations, OJT is the “default training method” used in lieu of more formalized training. Traditional OJT has been found to be somewhat erratic in that it can produce inconsistent or unequal results from individual to individual. In the writer’s experience, one year of OJT is equivalent to approximately 20 hours of classroom training.
OJT is limited by the skill (and experience) of the instructor and in some cases has been found to take up to twice as long as anticipated. It has been reported[2] that traditional OJT training could be replaced by a structured training approach with the result being training time reduced by some 72%, problem-solving ability increased by 130% and wasted time and effort reduced by 76%.
Why the “Hands-On” Approach?
Training based on a “read it, see it, do it” philosophy combines sound scientific and engineering principles with practical real-world experience and must include plenty of practical examples. Individuals who follow this approach not only learn the subject but also understand how to apply it in their everyday jobs. See you on the shop floor! IH
A Training Course Outline for Vacuum Heat Treatment
Vacuum heat treating can provide an example of a basic in-house training program that combines classroom instruction with training “on the shop floor.” Subjects include (in broad terms): vacuum basics, vacuum principles and vacuum applications. Here’s a typical course outline:
A. Introduction to Heat Treating
1. What is heating treating, and why do we do it?
2. Heat-treating processes and equipment
B. Fundamentals of Vacuum
1. What is vacuum?
2. Common vacuum units
3. Pump-down effects (the theory of gases)
4. Vapor pressure, partial pressure
C. Principles of Vacuum and Vacuum Furnaces
1. Vacuum pumping systems (the molecule movers)
2. Vacuum measurement (the molecule counters)
3. Vacuum valves
D. Vacuum Fundamentals
1. Vapor pressure, partial pressure and related topics
E. Introduction to Vacuum Furnace Equipment
1. Types of vacuum furnaces
2. Hot-zone construction – Materials of construction
3. Heating elements – Types and repair methods
4. Control strategies and instrumentation choices
5. Water systems
F. Vacuum Heat-Treating Applications
1. Introduction to vacuum processing
2. The importance of cleaning
3. Annealing and partial annealing (stress relief)
4. Normalizing
5. Fundamentals of brazing
6. Heat treatment of stainless steels
7. Heat treatment of tool steels
8. Low-pressure (vacuum) carburizing and carbonitriding
9. Sintering
G. Quenching in Vacuum
1. Factors influencing part distortion and quenching
2. Fundamentals of gas pressure quenching
3. Fundamentals of oil quenching
H. Troubleshooting
1. Maintenance practices, procedures and tips
2. Maintenance of vacuum subsystems and components
3. Troubleshooting instrumentation and controls
4. The why, when and how of leak checking a vacuum furnace (leak rates, leak detection and leak repair)
5. Setting up a PLANNED preventative-maintenance program
6. Work preparation (loading)
7. Baskets, fixtures and racks – Design, alloy selection, maintenance
8. Diffusion bonding, eutectic melting, outgassing and related topics
I. Testing and Quality Assurance
1. Types of mechanical testing: Understanding the basics
2. Principles of hardness testing (Rockwell and Rockwell superficial)
3. Practical considerations for successful hardness testing
4. Hardness and hardenability
5. Failure analysis – Nondestructive testing methods
J. Basic Skill Reinforcement
1. Temperature scales
2. Temperature measurement methods (What is a thermocouple?)
3. Systems of units
4. Material types and designations
5. Surface oxidation
K. Miscellaneous
1. Industry standards and specifications (Nadcap, CQI-9, AMS, ASTM, etc.)
L. Safety
1. Safety in the heat-treat shop
2. Gas safety
3. Confined-entry spaces
M . Management Overview
1. Management responsibilities
2. Lean, green and agile manufacturing and lean heat treatment
3. The challenges ahead