Cold Working of Metals — Effects on Structure, Properties, and Accuracy During cold working operations (performed below recrystallisation temperature), which combined outcomes are typically observed?

Introduction / Context:
Cold working processes such as cold rolling, drawing, swaging, and press forming plastically deform metals below their recrystallisation temperature. These processes influence microstructure, mechanical properties, and dimensional control. Knowing the combined effects guides process selection and heat-treatment planning.

Given Data / Assumptions:

• Temperature: below recrystallisation for the alloy.
• Plastic deformation induces dislocations and work hardening.
• Tooling and presses provide good geometric control.

Concept / Approach:
Cold deformation increases dislocation density, distorting grains and producing texture (preferred orientation). This “work hardening” raises strength and hardness while lowering ductility. Because thermal expansion is minimal and elastic springback can be predicted, tight tolerances and fine surface finish are achievable, especially compared to hot working.

Step-by-Step Solution:
Microstructure: distortion and stored strain → option A true.Properties: work hardening boosts strength/hardness → option B true.Accuracy: low thermal effects allow close tolerances → option C true.Hence, the correct comprehensive choice is option D.

Verification / Alternative check:
Typical stress–strain curves show higher yield strength after cold working, and process capability studies confirm improved dimensional control.

Why Other Options Are Wrong:
Selecting only one benefit ignores the broader effect profile of cold working.“None of these” conflicts with established metallurgy.

Common Pitfalls:
Confusing increased strength with improved ductility; ductility generally decreases unless annealed afterward.

Final Answer:
all of the above