The American Motors Corporation 1977 model Gremlin and Hornet passenger cars utilize SAE 980 XK high strength low alloy (HSLA) steel as the material from which is fabricated the body side rear sills. This is the first known application of 80 ksi (552 MPa) HSLA steel for a unitized auto body major structural component. The selection of 980 XK HSLA steel enabled AMC advanced chassis engineers to successfully modify an existing rear body structure to withstand the rear barrier impact test required for 1977 model passenger cars by FMVSS #301. This paper presents the welding, assembly, and quality control procedures developed by AMC manufacturing engineers to assure that production body structures meet all design specifications.
Joining the higher strength steels with arc welding demands greater care by all-designer through welder-than normally given mild steel. Proper design and welding procedures will produce crack-free welds that resist failure in service. This paper discusses weld strength allowables for high strength steels under steady and fatigue loading. It also analyzes and relates the effect of controlled heat input (preheat, welding procedure and postheat) to residual stresses, cracking, and distortion. Most of the problems experienced in welding high strength alloy steels can be predicted in advance and eliminated.
This SAE Recommended Practice defines the best known techniques for evaluating peak and locked wheel braking traction. It covers an important phase of tire braking traction, namely, the wet or dry pavement straight ahead conditions. However, this is but a small portion of the whole field of tire traction. As test procedures are established for other phases of this complex study, additional supplementary procedures will be written. A discussion of this entire subject is contained in Appendix B to this recommended practice.
THE control of grain size has facilitated the development of new steels and modifications in heat-treating processes, Mr. Davis announces. His paper deals with modern progress in the steel mill, the employment of the Carbometer and Turbidimeter, lime-silica ratio and the newer deoxidizers employed to aid steel quality. The internally heated immersion bath has been a distinct advancement in salt-bath hardening and enables longer pots to be practical, he explains. Dry cyaniding with ammonia gas may eventually obsolete cyanides and activated baths, in the opinion of the author. Gas carburizing gradually is supplanting box carburizing, he reports, and many large heat-treating units carburize, quench wash and temper mechanically. Also, a late gas carburizing furnace eliminates the employment of a muffle.
Type 301 stainless steel is an austenitic, chromium-nickel stainless steel with exceptional strength and fabrication characteristics. This paper describes these characteristics and their role in the design and manufacture of automotive wheel trim. Data are provided on deep drawing and press forming of Type 301, and comparisons are made to aluminum alloy 5252-H25.
The growth of galvanized steel in the automotive industry in the last ten years has spurred the development of several new and improved grades. The American Iron and Steel Institute has published a guide to these new grades that will help identify the various trade names and distinguish between the different types of galvanized steel now available.
Vacuum metallized parts must comply with the antiglare regulations as set forth by the General Services Administration. This is in spite of the inherent brightness of a vaporized aluminum plate. Ways and means to satisfying these regulations are discussed, and advantages and disadvantages of the several different possible solutions are weighed.
This paper describes the development of a process that will mold a urethane resin in the form of a laminate. The urethane resin is a most unusual material: it can be formulated to produce thermosetting foam of almost any density, and the formulation can also be made to produce either a flexible or rigid foam. It has excellent adhesive properties, which we have used to make the laminate. The process produces a laminate of two skins, which are combined with a film of urethane resin in its liquid form. This combination, when placed in a heated mold, causes the resin to expand until both skins reach the confine of the mold. This then cures to the shape of the mold and the texture of its surface, making it possible to mold sculptured and formed shapes or panels, which can be used for interior trim for automobiles.
Phosphate coatings have been developed to serve many useful applications because of variations of coating obtainable, because of improvement in control, and development of new processes. Important characteristics for the following facets are compared such as, typical application and functions; new developments and improvements; types of coatings, final and supplementary finishes; basic processes; controls of process and quality; requirements of coatings; problems posed in applying; and effects of design and handling. Phosphate coatings have an essential role in industry not only for corrosion preventive purposes but also for functional applications and for use as a production tool
Over the last ten years, the plastics industry has been under pressure by many industries, such as automotive, to resolve issues from an application point of view, such as value engineering, part quality, and time to market. Value engineering programs have been a major thrust for the last several years in many industries. These programs have taken the form of low cost materials, systems integration, part weight reduction, and lower fabrication costs. The automotive industry, forced by foreign competition during the 1980s, has also led the way in providing an emphasis toward improved part quality resulting in longer part life cycles. In addition, automotive producers are shortening their design engineering phase which has caused the plastics industry to find methods to more rapidly move technology from research and development to end-use applications.