"温度自记曲线" can be translated into English as "temperature self-recording curve" or "thermograph curve" (though "thermograph curve" is more specific to the device called a thermograph that records temperature, the general concept can still be conveyed by it in some contexts).
In most scientific or technical contexts, "temperature self-recording curve" would be the more precise and commonly used term, as it directly describes the curve that is automatically recorded by a temperature-recording device.